Road traffic was also disrupted at several places after agitating teachers blocked national and state highways, the officer added.

The strike, supported by opposition parties, comes two days after nearly 50 fixed-pay teachers on contract, including women, were injured in police lathicharge here. About 2.5 lakh contractual teachers in Bihar are demanding permanent jobs and pay parity with regular teachers.

An officer at the police headquarters here said that thousands of contractual teachers took to streets Thursday to press for their demands.

In view of the strike, security has been beefed up in the Bihar capital Patna.

"We have deployed additional forces in sensitive areas. Besides, patrolling has been intensified and all police stations have been put on alert," Amrit Raj, senior superintendent of police in Patna said.

Amrit Raj, however, said that normal life in Patna remained unaffected by the strike as markets and other business establishments remained open.

Pradeep Kumar, leader of Bihar Rajya Shikshak Sangharsh Morcha, an umbrella body of the contractual teachers, said they would boycott the matriculation examination scheduled in March.

"Academic work in all primary and secondary schools would be boycotted by the teachers against the brutal police action" he said.

The Bihar Rajya Prathamik Shikshak Sangh has also said that all primary school teachers will go on mass leave from Thursday and boycott all the examination related work.

Thousands of teachers staged protests at various places in Patna, district headquarters and development blocks across the state.

Puran Kumar, a leader of protesting teachers, said that 11 first information reports (FIRs) related to arson and violence were lodged in Patna Wednesday, and 53 contractual teachers were sent to judicial custody.