Thousands of flood victims waiting in line for relief vouchers Sunday stampeded into a government-run distribution center in southern India, killing at least 42 people and injuring 37, police said.

Nearly 3,000 people lined up before dawn along a narrow street leading to a school where they were to collect coupons for provisions, R. Nataraj, the city's police chief, told The Associated Press.

Police asked the crowd to leave, saying the center would not open for hours, but the victims demanded that the vouchers be distributed immediately. When the school gates opened to let in a vehicle, the crowd mistakenly assumed the center had opened and surged forward, he said.

A stampede ensued, crushing those in the front, mostly women. At least 11 policemen who tried to control the crowd were among the injured.

"We had posted several policemen at all relief centers expecting such commotion, but what happened here was beyond the power of all," Nataraj said.

A witness said people became restless after waiting for hours and began to rush forward after seeing some movement at the head of the line.

"Many jostled with each other to get ahead, but nobody knew who started the whole thing," said S. Hameed, who lives nearby.

The government of Tamil Nadu state said in a statement that it had asked a retired High Court judge to head an inquiry into the cause of the incident.

The flood victims, whose homes have been damaged or destroyed by recent downpours, lined up to collect coupons that would have helped them get rice, kerosene and $22 in cash.

The relief center in a government-run school did not house victims.

This was the second such incident in Madras, the capital of Tamil Nadu state, in the past two months. In November, six people were killed and 20 injured in another stampede near a relief camp in a northern district.

At least 430 people have been killed in Tamil Nadu and half a million left homeless by storms that have pounded the state since late October.

The state receives most of its annual rainfall from the northeast monsoon, which is often accompanied by cyclonic activity in the Bay of Bengal.