Supporters of an unsuccessful presidential candidate clashed with security forces and set fire to a police dormitory and vehicles in the Indonesian capital on Wednesday after the release of official election results. The situation turned violent late Tuesday when protesters tried to force their way into the offices of the election supervisory agency and clashes continued through the night, National Police spokesman Dedi Prasetyo said. More than 20 suspected provocateurs were arrested, he said Wednesday. KompasTV showed protesters throwing rocks, a paramilitary police dormitory on fire, and hundreds of riot police in a central neighborhood. Indonesia’s Election Commission on Tuesday said President Joko Widodo had won a second term with 55.5% of the vote in the April 17 election. Former special forces general Prabowo Subianto has refused to accept the results and declared himself the winner. His campaign plans to challenge the election in the Constitutional Court. They allege massive fraud but have provided no credible evidence. Jakarta police spokesman Argo Yuwono said police used tear gas and water cannon against protesters who threw rocks, molotov cocktails and burning projectiles. The government had deployed some 50,000 police and soldiers in Jakarta in anticipation of protests, said Yuwono. Many residents have left the city and parts of the downtown are closed to traffic with the election supervisory agency and election commission barricaded with razor wire. In the past week, authorities have arrested three pro-Subianto activists on suspicion of treason, said Prasetyo, including a retired general and former commander of Indonesia’s special forces. Police allege there was a plot to seize crucial government buildings in Jakarta.