Kinshasa - Fresh clashes erupted on Tuesday as demonstrators rampaged in the Democratic Republic of Congo a day after deadly protests over a draft law that would enable President Joseph Kabila to extend his stay in power.Hundreds of youths torched a town hall in Ngaba, a southern neighbourhood of the capital Kinshasa, while several prisoners escaped from a neighbouring building. Looters also made off with police guns stored at the site.Opposition parties have called for mass demonstrations against the new electoral bill being debated in the Senate.The army and police arrested at least 20 people as protesters hurled rocks at state buildings, public buses and even passing cars. Soldiers fired in the air to scare off looters who targeted a Chinese-owned store."We're tired of Kabila. He has to go," a protester told AFP as six vehicles burned nearby. In an apparent attempt to keep a lid on the protests, authorities have shut down the Internet in the capital Kinshasa.The unrest is the latest upheaval to rock the troubled central African county, which has been plagued by multiple wars and weakened by ineffectual governance for decades.Four people were killed Monday, according to the authorities, when security forces forcibly dispersed thousands of protesters in Kinshasa, a sprawling city of some nine million people.The opposition is demanding that Kabila - who has been in power for 14 years - quit when his mandate expires in 2016.About 350 youths massed again on Tuesday in the central district of Lemba, where security forces put out fires set with blazing tyres, and about 30 riot police were trying to restore order, an AFP journalist said.Police have cordoned off a broad perimeter around parliament, known as the Palace of the People, to stop protesters interrupting the Senate session, which began studying the controversial bill already passed by the lower house on Saturday.The three main opposition parties jointly called on Kinshasa residents to "massively occupy" the premises and stall the debate.New electoral roll Government spokesperson Lambert Mende said two policemen who died on Monday were killed by bullets, saying the other two killed were "looters".Witnesses said police had fired live ammunition to disperse demonstrators.At least 10 people were admitted to hospital with gunshot wounds, medical staff reported, while the opposition and diplomatic sources said the casualty figures were most likely higher than the official toll.A day after the bloodshed, mobile phone operators said they had been told to shut down the Internet. "The National Intelligence Agency gave us the order to block the Internet in Kinshasa until further notice," the manager of one service provider told AFP. Many African presidents have tried, and often succeeded, to stay in power by rewriting their countries' constitutions to get rid of limits on presidential terms.Kabila, now 43, first came to power in January 2001 when Kinshasa politicians rushed to make the young soldier head of state after the assassination of his father, President Laurent Kabila.Prolong mandateIn 2006, Kabila was returned to office in the DRC's first free election since independence from Belgium in 1960. He began his second and last five-year constitutional term after a hotly disputed vote in 2011.His opponents believe that Kabila wants to prolong his mandate by making the presidential and parliamentary elections contingent on a new electoral roll, after a census across the vast mineral-rich country set to begin this year.The government has acknowledged that the census could delay elections due at the end of 2016, but regional analysts and diplomats estimate the process could take up to three years.France voiced concern over the "recurring trouble" accompanying the debate of the election law.Foreign ministry spokesperson Romain Nadal said Paris was urging all parties to negotiate on the proposed reforms "in a consensual fashion, respecting the Democratic Republic of Congo's constitution and civil liberties".Last year, Burkina Faso's president Blaise Compaore was driven from power when he tried to change the constitution to extend his mandate.