Anti-corruption activist Arvind Kejriwal and six others were detained here Sunday while trying to stage protests near Prime Minister Manmohan Singh's residence and two other places. But police released them after about two hours at the Mandir Marg police station when scores of Kejriwal supporters gathered there, raising slogans against police and the government. Police tried to take them to Bawana but Kejriwal refused to go till there was a FIR. After the group was let off, Kejriwal and everyone made it to Jantar Mantar in the heart of the capital and vowed to return to Manmohan Singh's residence and the other two protest venues. IAC had called for protests Sunday outside Manmohan Singh and BJP president Nitin Gadkari's houses, accusing both the Congress and BJP for alleged irregularities in coal blocks allocation. Kejriwal was stopped near a police barricade close to Manmohan Singh's residence along with fellow activists Gopal Rai and Vishal Sharma. Another IAC leader, Manish Sisodia, was detained outside Congress president Sonia Gandhi's residence along with a colleague and taken to the police station. IAC member Sanjay Singh and a colleague was picked up near Gadkari's house. At Jantar Mantar, IAC activists numbering around 400 staged a noisy demonstration against corruption for which they held both the Congress and the Bharatiya Janata Party responsible. Some of the protesters carried placards of Manmohan Singh.