The death toll from a powerful earthquake that rumbled through the Himalayan mountains of Nepal and eastern India before dawn Sunday rose to at least 400, officials and news reports said.
Thousands of Indians and Nepalese rushed into the streets as the temblor rocked a 1,000-mile belt along the India-Nepal border for about 45 seconds.
More than 3,000 people were injured in the quake, which seismologists called the deadliest to strike the Himalayan region since 1950.
The Seismological Observatory in New Delhi said the quake measured 6.5 on the Richter scale and was centered about 40 to 50 miles northeast of Darbhanga, a town of about 800,000 in the eastern state of Bihar.
Indian officials said at least 125 people were killed and 2,000 injured in Bihar, while government television put the number of dead at more than 300. More than 25,000 houses were destroyed in the state, officials said.
The Press Trust of India news agency said 17 children were killed in Darbhanga when the roof of a school caved in.
State-run Radio Nepal said at least 281 people were killed in towns near the border, and Nepalese officials said that more than 1,000 were injured.
The quake also jolted parts of northern Bangladesh and the capital of Dhaka. Police said about 50 people were feared drowned when waves generated by the quake swamped at least five passenger boats in the Jamuna River, 60 miles southwest of Dhaka.
Landslides knocked out communication links on both sides of the border, preventing officials from obtaining information about casualties or damage from remote areas.
The monsoon rains, which hit the subcontinent in late June and usually continue through September, also were hampering rescue operations. More than 50 villages were flooded after the quake shifted dikes and levees.
In Nepal, a Foreign Ministry official said at least 500 people were injured and thousands of houses have collapsed. Other officials put the toll of injured at more than 1,000.
"Most of (the victims were) buried alive under collapsed houses," said Indra Shrestha, a social worker involved in rescue operations in Dharan Bazar, a township of about 100,000 people near the Indian border.
In the capital of Katmandu, the Nepal Red Cross Society issued an urgent appeal for blood donors, saying hundreds of units of blood were needed in the industrial town of Biratnagar alone.
Prime Minister Marich Man Singh Shrestha, who returned to Nepal on Sunday after attending the funeral of Pakistani President Zia ul-Haq in Islamabad, called an emergency Cabinet meeting to deal with the disaster.
Officials in both Nepal and India rushed medical teams, clothes and other relief material to the disaster areas. Indian Prime Minister Rajiv Gandhi planned to visit the region today to survey the damage.
The Press Trust news agency reported from Patna, the capital of Bihar, that many residents have moved their belongings into the streets, apparently frightened that another temblor would bring down their damaged houses.
The agency said the quake caused dozens of houses to collapse in Siliguri, 310 miles north of Calcutta, sending hundreds of people scurrying for shelter.
"Women started blowing conch shells in the age-old belief that such an act would appease the wrath of weather gods and the quake would be contained," the news agency said.
The quake also was felt in the heavily populated states of Uttar Pradesh, West Bengal and Orissa, United News of India said.
In the Madhubani district, a river jumped its banks after the quake shifted levees and flooded nearly 50 villages, the United News of India said.
Officials said at least 45 people died in the district, but it was not known whether the deaths were due to floods or collapsing houses.
The Bhootahi Balan River continued to rise more than 12 hours after the quake, the officials said.
The worst quake in the Indian subcontinent occurred in 1935, when 30,000 people died in Quetta, India, in what is now Pakistan.
Nepal's deadliest earthquake occurred in 1934, when more than 10,700 people died.