GUWAHATI - Authorities in a remote Indian state on Thursday said they were working hard to prevent the eruption of epidemics in crowded camps sheltering some 400,000 people after weeks of deadly ethnic violence.

Some 250 physicians were working “round-the clock” to head off any outbreaks of sickness in the camps where thousands of families have taken shelter after violence erupted in the northeastern state of Assam.

At least 77 people have died in the clashes that began in early July, Home Minister Sushilkumar Shinde told parliament in New Delhi. “We’ve sounded a health alert and asked all doctors and paramedics to fan out to 250 relief camps where people displaced in the clashes are sheltered,” state Health Minister Himanta Biswa Sarma said.

“Our doctors have treated more than 150,000 people and this figure is not a small number. But we are lucky there has been no outbreak of any epidemic in the camps despite the very large number of inmates,” he said.

The federal home minister said police pickets were being set up in riot-hit villages to give confidence to people to return to their homes.

“A plan is in place go restore confidence among the people and it is proposed to set up 104 police pickets in sensitive villages of which 99 have already been established,” Shinde told  parliament.

He said some 5,300 homes were torched in the riots that erupted between indigenous Bodo tribes and Muslim settlers over long-running land disputes and immigration issues. Some 244 villages were affected in the clashes, he added.

Rival groups from both sides have raided villages, killing or wounding people with sticks and machetes, and torched homes in Assam, which has a long history of ethnic and tribal insurgencies.

Prime Minister Manmohan Singh toured the oil-rich state last month.

The international rights group Human Rights Watch says tensions had been building for more than two months between the Bodos and the Muslims, which have clashed in the past over access to land and resources.