Helicopters airdropped emergency supplies to Himalayan villages worst-hit by a quake that killed at least 81 people in India, Nepal and China, while earthmovers pushed through debris clogging precipitous valleys.
Soldiers in the northeastern Indian state of Sikkim cleared a path to Mangan, one of the towns closest to the epicenter of Sunday's 6.9-magnitude quake, but many other communities remained cut off and authorities fear the death toll will rise once rescuers reach them.
Indian army helicopters ferried rescuers and dropped food and supplies to still-inaccessible villages in Sikkim, a sparsely populated and almost entirely mountainous region that was an independent protectorate before becoming an Indian state in 1975. It borders Nepal, Bangladesh, Bhutan and the Chinese region of Tibet.
The quake killed at least 50 people in Sikkim, said the state's top official, Karma Gyatso.
India's Home Secretary R. K. Singh told reporters that 12 people were killed in West Bengal and six others in Bihar state. Authorities in neighboring Nepal reported six deaths, while China's official Xinhua news agency reported seven deaths in Tibet.
Army helicopters were still conducting aerial surveys of the quake zone, though local authorities already have reported extensive damage to homes and buildings across Sikkim, Gyatso said.
In Nepal, officials said six people were killed when houses collapsed near the capital Katmandu, bringing down an earlier figure of seven deaths due to the quake.
The region has been hit by major earthquakes in the past, including in 1950 and 1897.