Violence-torn Assam state remains tense

More than 170,000 people have fled their homes

The situation in India's violence-torn Assam state continues to be tense, with the death toll in fighting there rising to 40, reports say.

More than 170,000 people have fled their homes after fighting between indigenous Bodo tribes and Muslim settlers in Kokrajhar and Chirang.

Security forces have been given shoot-on-sight orders and a curfew has been imposed in the troubled areas.

Rioters have continued sporadic attacks, setting homes on fire.

There has been tension between indigenous groups and Muslim Bengali migrants in Assam for many years.

Railway guards

The federal government has asked the Assam government to arrest the "ringleaders" of the violence, and has deployed 2,000 security forces to guard the railway tracks linking the state with the rest of the country.

Some villagers in Chirang district have moved to relief camps

Railway links were disrupted after local people threw stones at an express train travelling through the area, damaging four coaches.

Though many roads in the affected districts remained closed, train services resumed on Wednesday under heavy security, railway officials told the Associated Press news agency.

Police say that the clashes began when unidentified men killed four youths on Friday night in Kokrajhar, an area dominated by the Bodo tribe.

They say that armed Bodos attacked Muslims in retaliation, suspecting they were behind the killings.

Soon afterwards unidentified groups set houses, schools and vehicles ablaze, police said, firing indiscriminately from automatic weapons in populated areas.