Over a dozen contract teachers were injured when hundreds of them, demanding regularisation and annual increment, clashed with the police here on Friday.

Taking out a protest march from Gandhi Maidan to R Block roundabout, some of the teachers tried to enter the Vidhan Sabha premises around 1 pm. The police then resorted to lathichage and used water cannons to disperse the protesters. No one, however, suffered serious injuries.

Calling it an “insult”, the RJD stalled the Assembly proceedings over the “attack” on the teachers for about 20 minutes. About10,000 striking teachers caused traffic disruptions and diversions in the main Patna area.

The contract teachers had taken exception to Chief Minister Nitish Kumar’s recent announcement in which he said that teachers would get increment after they passed an examination, held every three years. The Bihar government has appointed 2.5 lakh teachers in the last three years.

Bihar police spokesperson Additional Director General Of Police Neelmani, however, said policemen had to resort to lathicharge in defence. “Some policemen were hit by stones thrown by the teachers,” he added.