Patna, Aug 14 (IANS) Indefinite curfew continued for the third day Wednesday in Bihar's Nawada, following clashes between two communities in the last five days that claimed two lives and left over six people injured, officials said.

The state police headquarters has instructed the Criminal Investigation Department(CID) to probe the violence.

"The CID has begun investigations into how communal passions were stoked," a police official at the police headquarters here told IANS.

A district official in Nawada, speaking over telephone, said that Deputy Inspector General of Police Amit Lodha of the Criminal Investigation Department led the team that began the investigations, on the basis of four FIRs lodged in this connection.

Officials suspect two local leaders, who have been involved in illegal stone quarrying and sing mining in the district, of inciting communal hatred as part of business rivalry, one policeman in the district said.

Nawada District Magistrate Adesh Titarmare said curfew would not be relaxed Wednesday. Markets and educational institutions in Nawada town remained shut.

"The situation is tense but under control, with no report of any fresh clash from anywhere so far," the district magistrate said, adding that the National Security Act (NSA) would be invoked for preventive detention and swift action against troublemakers.

Curfew was imposed in the town after police Monday resorted to firing to quell a violent clash between two communities.

"Assembly of five or more people at any particular place and display of firearms have been banned," Nawada Superintendent of Police M.S. Dhillon said.

Dhillon said 39 people have so far been arrested in connection with the violence.

Additional security forces, including Rapid Action Force, have been deployed and patrolling intensified.

Police fired Monday when a mob attacked the Bundelkhand police station in Nawada, about 150 km from here, followed by the clashes.

Communal tension erupted Friday when an altercation over the menu occurred between a group of kanwarias (Hindu pilgrims) and another community at a roadside eatery in Nawada.

District officials said clashes continued after the death of a 20-year-old youth, Kundan Kumar, who was injured along with three others in police firing Saturday.

Kundan Kumar died at the Patna Medical College and Hospital Sunday.

District authorities had imposed curfew in Nawada for a few hours Saturday, but later lifted it.

Dhillon said Assistant Sub-Inspector Kamal Narain Singh of Nawada town police station has been suspended on charges of dereliction of duty.

Chief Minister Nitish Kumar expressed concern over the situation in Nawada, and directed officials to take stern action against anti-social elements. Nitish Kumar further appealed to people and political parties to help the government ensure social harmony in Nawada town.

"I will not allow communal tension to flare up, and the state government will take all steps for the restoration of peace and harmony," he said.