Malaysia has passed a controversial terror law aimed at tackling growing support for Islamic State extremists in the country in a move opponents denounced as a harsh blow for civil rights. The Prevention of Terrorism Act - passed in the capital Kuala Lumpur yesterday - officially enables authorities to detain suspected terrorists for two years without charge or trial. But it also allows for the authorities to apply for unlimited extensions after those two years expire - something that will be decided by a government-appointed terrorism board, not a judge and jury. The bill effectively reintroduces the controversial prospect of indefinite detention without trial in Malaysia - something Prime Minister Najib Razak originally repealed in 2012. Rise: Malaysian police said in January they had arrested a total of 120 people with suspected links or sympathies to the Islamic State terror group (pictured), or who had sought to travel to war-torn Syria or Iraq . Razak's political opponents and human rights groups had urged for the bill to be withdrawn, claiming it is 'open to abuse and is a grievous blow to democracy'. Human Rights Watch described it as 'a giant step backwards for human rights'. The legislation was passed after midnight, following 15 hours of debate, according to media reports. Its passage was not in doubt due to the ruling regime's majority in parliament. Authorities have expressed increasing alarm in the wake of ISIS' bloody jihad in Syria, which police say has drawn dozens of recruits from traditionally moderate, Muslim-majority Malaysia. Yesterday police said 17 people, including two who recently returned from Syria, had been arrested on suspicion of plotting terror attacks in  Kuala Lumpur. No further details were given. International: Malaysian authorities have expressed increasing alarm in the wake of ISIS' bloody jihad in Syria, which police say has drawn dozens of recruits from traditionally moderate, Muslim-majority Malaysia . Police said in January they had arrested a total of 120 people with suspected Islamic State links or sympathies, or who had sought to travel to Syria or Iraq. They also said 67 Malaysians were known at the time to have gone abroad to join IS jihadists, and that five had died fighting for the movement. The terrorism act has heightened worries in Malaysia over a deepening crackdown on civil liberties launched by the government in the wake of a 2013 election setback. The ruling United Malays National Organisation has been in charge since 1957, but faces possible defeat at the hands of an opposition that has campaigned against government corruption and alleged abuse of power. Dozens of government critics, including opposition politicians, academics, activists, and journalists, have been hit with sedition or other charges after criticising the regime. Leader: The bill effectively reintroduces the controversial prospect of indefinite detention without trial in Malaysia - something Prime Minister Najib Razak (pictured) originally repealed in 2012 . In particular, the terror legislation has revived concerns of a return to a previous draconian Internal Security Act that allowed detention without trial and was repeatedly used against opposition politicians. The ISA was scrapped in 2012 amid public pressure for political reform. 'The passage of this law is a giant step backwards for human rights in Malaysia that fundamentally calls into question the government's commitment to basic rights that are critical to the rule of law in a functioning democracy,' Human Rights Watch's deputy Asia director Phil Robertson said. 'Passage of this legislation raises serious concerns that Malaysia will return to practices of the past when government agents frequently used fear of indefinite detention to intimidate and silence outspoken critics.' The government did not immediately respond to a request for comment, but has said previously the law would not be used against anyone over their 'political' views.
Law allows police to hold suspects for two years without charge or trial . Government-appointed terror board can then decide to grant an extension . Opponents and human rights groups said the bill was 'open to abuse' and represents 'a giant step backwards for human rights' Law has been introduced to combat the growing threat of ISIS in Malaysia .