(CNN)Vigilante motorists in New Zealand have taken to snatching the car keys of foreign drivers amid rising concern over dangerous driving by tourists. New Zealand media have reported five cases this year of locals forcibly taking the keys of foreign motorists after witnessing driving that concerned them. All the incidents -- which have been condemned by authorities -- took place in the South Island, which draws tourists from around the world for its rugged scenery, including lakes and mountains featured in director Peter Jackson's "Lord of the Rings" films. The incidents occurred amid heightened public concern over tourist driving standards, with eight people killed in crashes involving foreign drivers in the space of a fortnight last month. Among the dead were a family of four from Hong Kong who were killed when their car crossed the center line and collided with a logging truck. The key snatchings have even prompted Prime Minister John Key to weigh in on the issue, advising that "people taking the law into their own hands is not sensible." New Zealand Police Assistant Commissioner of Road Policing Dave Cliff said the confiscations existed in a legal gray area, as there was no explicit statute dealing with the issue. Although there might be exceptional circumstances where taking someone's keys could be legally justified, such as preventing drunken driving, he said, "in the vast majority of cases, it won't be." "That extends to physically assaulting or abusing someone in response to their driving, which is simply not acceptable, and anyone found doing so should expect to face the consequences," he said. Diesel mechanic Robert Penman of Dunedin made headlines last month after he took the keys of a Chinese couple who had stopped their car on a narrow single-lane road to take pictures, causing a backlog of vehicles behind them. "I was coming into town with my wife and son and came around the corner, and there was a car stopped in the middle of the road," he told CNN affiliate TVNZ. He called police and took their keys as "a safety thing, you know, timeframe for police to get there," he said. The New Zealand Transport Agency later revealed that Penman was driving on an expired license himself. Penman told local media it was not the first time he had taken a tourist's car keys. Only 6% of crashes in New Zealand involve foreign drivers, according to the latest figures provided by the Ministry of Transport. But in some remote regions of the South Island particularly popular with tourists for their scenery -- such as the Mackenzie, Southland, Queenstown-Lakes and Kaikoura districts -- foreign drivers are involved in about a quarter of all crashes. In Westland District, on the South Island's rugged West Coast, foreign drivers are involved in 37% of road crashes resulting in death or injury. Tony Kokshoorn, mayor of the neighboring Grey District, said tourist driving behavior was a major problem in the region and attributed the issue to tourists from countries that drive on the right. New Zealanders drive on the left. "There's a huge number of tourists coming through to these destinations because of the scenery, but the scenery is a problem," he said. "There's so many beautiful sights to see that they're not concentrating on their driving. Once they lose their concentration, they tend to fall into old habits and drive on the right. Even for 20 seconds, it can cause damage." A Ministry of Transport spokesperson said that while this was a factor, figures showed that Australian and British drivers were involved in the most crashes overall, "so unfamiliarity with which side of the road to drive on is not the only factor." Kokshoorn said that he had seen three cases of tourists driving on the wrong side of the road recently but that the vigilante approach -- which had seen a visitor to his town punched in the face as he was stripped of his keys last month -- was "disgraceful." He said the best approach was better education on local driving conditions for foreign drivers, particularly at the rental companies where they picked up their vehicles. Anyone with a foreign drivers license or permit is able to drive in New Zealand for up to a year. Associate Transport Minister Craig Foss said the government recognized that "many people are concerned with poor driving behavior on challenging roads in and around popular tourist destinations" and had established a project in response. The measures include improvements to roading, such as "keep left" signage and no-passing markings on the extensive stretches of single-lane highway, and educational resources targeted at visiting drivers, including many targeting the growing Chinese market. Kokshoorn said it was important to "strike the right balance" in getting the message to foreign drivers to take care on the unfamiliar roads. "We value tourism and the dollars it brings to New Zealand, especially to our region here. We don't want to put tourists off, but we want them to be safe in our country," he said. "You cross that center line, and anything's possible." CNN's David Molko contributed to this report.
Five tourists have had their car keys snatched by vigilantes this year . The confiscations have taken place amid rising concern over tourist driving behavior . In popular Westland, 37% of serious crashes have involved foreign drivers .