Around 500 people were arrested on Tuesday as thousands of students staged a protest in the state capital Patna, clashing with police and setting vehicles and a market on fire. Police said around 50 vehicles were damaged in the clashes.

The violence erupted after opposition parties and youth organisations called a general strike over the killing of three youths in a police encounter on Saturday night. The police say they opened fire "during an encounter with robbers" but deny they acted illegally.

The victims' families, however, allege they were innocent and the police shot them in "cold blood" during a "fake encounter". Senior superintendent of police, Sunil Kumar, said the officer in charge of the local police station had been arrested and a case lodged against the policemen involved.

"The accident has happened and the guilty cannot be hanged overnight. The probe is on and suitable action has already been taken," added police director general R.R. Prasad. State home secretary R.J.M. Pillai said action would be taken against the policemen if they were found guilty. Opposition parties said they were observing Wednesday as a "black day" and called a statewide general strike on Friday. - AFP