A parcel bomb delivered to the Handwerkskammer trades association in Berlin last week was another attempt to blackmail German logistics giant DHL, investigators said on Tuesday.

"It is highly likely that the package was sent by the perpetrator or perpetrators who are trying to blackmail package delivery service DHL for millions (of euros)," said Torsten Herbst, a spokesman for the Brandenburg police department.

The approximately 15-centimeter-by-15-centimeter (6-inch-by-6-inch) package was found in the mailbox of the trade association in the Kreuzberg district last Thursday. A worker became suspicious after noticing wires protruding from the package.

A bomb disposal team diffused the bomb without an explosion being set off. Police said the size of the package meant that it could have seriously injured people had it exploded.

The bomb package was the fourth believed to be part of the extortion scheme against DHL in recent months.

Read more: Threats like DHL extortion plot in Potsdam more common than you think

In November, a parcel bomb was found in Frankfurt an der Oder. In December, a parcel bomb delivered to a pharmacy in Potsdam forced the brief closure of one of the city's Christmas markets. In January, a bank in Berlin received a package containing powder and fireworks.

Each evening at 1830 UTC, DW's editors send out a selection of the day's hard news and quality feature journalism. You can sign up to receive it directly here. </s> It is the fourth parcel bomb in recent months blamed on the blackmailer, who has demanded €10 million worth of bitcoins from the parcel delivery service DHL.

The latest parcel containing explosive material was sent to the Berlin Chamber of Crafts and "can in all likelihood be attributed to the DHL extortionist or extortionists," a Potsdam police spokesman told AFP.

A female employee at the trade association contacted the police on Thursday after she noticed wires protruding from the package.

Specialists were able to defuse the parcel without having to carry out a controlled explosion.

German police have been hunting for one or more suspects ever since a DHL parcel containing nails, screws and explosive powder from Polish fireworks, was received by a pharmacy in the city of Potsdam, near Berlin, in December.

That package failed to detonate upon opening but nevertheless prompted police to clear the nearby Christmas market as a precaution.

The evacuation revived fears of the jihadist attack on a Berlin Christmas market a year earlier, which killed 12 people.

Police later discovered a message inside the package threatening further parcel bombs unless DHL made a €10-million, untraceable payment in the virtual currency bitcoin.

A similar package was sent to an online retailer in the eastern city of Frankfurt an der Oder in November, believed to have come from the same source.

Another parcel bomb linked to the extortion plot was delivered to a Berlin bank in January, containing a detonator and what appeared to be powder from fireworks. It too was defused by police. </s> Image caption The device sent to Heathrow Airport caught fire when staff opened it

Counter-terror police are investigating three packages containing explosives found at Heathrow Airport, London City Airport and Waterloo station.

The "small improvised explosive devices" were found in A4 postal bags, the Metropolitan Police said.

The force's Counter Terrorism Command is treating it as a "linked series" and "keeping an open mind" about motives.

Irish police are assisting the Met as the Heathrow and Waterloo packages had Republic of Ireland stamps.

Heathrow's Compass Centre was evacuated after a package was reported to police at about 09:55 GMT.

The device caught fire when staff opened the bag.

Image caption A second explosive was found in the post room at Waterloo station with the same "Love & Wedding" stamps

Scotland Yard said: "The packages - all A4-sized white postal bags containing yellow Jiffy bags - have been assessed by specialist officers to be small improvised explosive devices.

"These devices, at this early stage of the investigation, appear capable of igniting an initially small fire when opened."

A Heathrow spokeswoman said the airport would support the police investigation into the "criminal act".

The Gardaí confirmed it was also assisting the Met.

Ireland's postal service identified the stamps as its "Love & Wedding" design for greeting cards, wedding invitations and thank-you cards.

The Compass Centre, which is an office for Heathrow staff rather than part of the passenger terminals, remains closed.

The picture of the jiffy bag addressed to Waterloo appears to show its sender's address as Bus Eireann, Dublin.

The operator said police had not been in touch, with a spokeswoman saying: "Bus Eireann are currently not aware of this and we have no further comment."

Analysis: BBC News Home Affairs Correspondent Daniel Sandford

Working explosive devices being sent through the mail - or letter bombs - are very rare in the UK.

Fortunately these packages only appear to be designed to start a very small fire - the one that went off just melted part of its own plastic envelope, and the other two were not opened.

But there is sufficient concern about today's incidents for them to be investigated as a linked series by Scotland Yard's Counter Terrorism Command.

This means the full weight of resources and expertise of one of the world's most experienced counter terrorism teams will be trying to get to the bottom of who sent the packages and why.

The motive is unclear. It could be anything from Irish republicanism to a grievance against transport companies. Other possibilities include someone with strong opinions about Brexit or someone with mental health problems.

The devices do not seem to be capable of causing serious injury, so they were probably intended to have a nuisance effect and to generate publicity, which they have successfully done.

Police will be hoping the series is now over.

Two more packages were found in the capital over the next three hours.

An area of Waterloo station was cordoned off after a second package was discovered in the post room at about 11:40, the BBC understands.

One worker among a group of staff outside the Network Rail office said he found the package.

Asked about the discovery, he said: "I'm sorry, I've been told I can't talk about it."

About 100 workers were evacuated from City Aviation House at City Airport in Newham after a third package was reported at about 12:10.

City Aviation House is a two-minute walk from the passenger terminal.

Staff returned to the office at about 16:00.

The second and third packages were not opened and have since been "made safe", police said.

Flights were not affected but Docklands Light Railway trains did not stop at City Airport for about an hour during the investigation.

Image caption A cordon was in place at Waterloo station, where one of the devices was found at 11:40

Assistant Chief Constable Sean O'Callaghan, from British Transport Police, said commuters should feel "safe and reassured" while travelling.

"Officers will be highly visible on station concourses, on board trains as well as the London Underground network," he added.

"Passengers are of course the eyes and ears of the network and we want to hear from you if you see something that doesn't look right."

Transport Secretary Chris Grayling urged people to report "anything suspicious" to police, while Mayor of London Sadiq Khan added: "Our thanks go to police, security, transport staff and all involved for their swift actions to keep our city safe." </s> French police have arrested two men after a suspected parcel bomb exploded in Lyon last week, injuring 13 people.

The device, packed with screws and ball bearings, detonated outside a bakery on Friday afternoon.

One of the men arrested, a 24-year-old, is the suspected bomber, prosecutors say. No details have been given on the other.

Police had been hunting for a man seen cycling near the scene of the blast wearing a balaclava and rucksack.

Anti-terrorist prosecutors are leading the investigation, co-ordinating with Lyon police and France's internal security service, the DGSI.

The explosion struck near the corner of two crowded pedestrian streets in Lyon's historic city centre.

Investigators have reportedly recovered screws, ball bearings, along with a printed circuit, batteries and a remote-controlled trigger device.

Denis Broliquier, the city's district mayor, told press that "the charge was too small to kill," and a government source told AFP news agency it had been a "relatively weak explosive charge".

Those hurt, including a girl aged eight, appear to have suffered superficial injuries.

French Interior Minister Christophe Castaner confirmed one of the arrests in a Tweet on Monday, saying joint action by several agencies had been "decisive".

Gérard Collomb, Mayor of Lyon, told local media that a second man was also arrested without giving further detail.

No-one has claimed responsibility for the attack.

The last time a parcel bomb had exploded in France was in 2007 when a device killed one person and injured another in front of a law office in Paris. Police never found the bomber.

Jihadist gun and bomb attacks have killed more than 250 people in France since 2015 and the country remains on high alert, with military patrols a regular feature of security in cities including Lyon.
German police defuse a parcel bomb in Berlin. It is thought to be the fourth device sent by a blackmailer targetting DHL.