Indian authorities have begun air-dropping relief supplies to survivors of an earthquake that killed at least 63 people in northeastern India and neighboring countries.

Authorities said Monday Indian Air Force helicopters made several food drops to villagers in the mountainous state of Sikkim, the epicenter of the magnitude 6.9 earthquake that struck the region a day earlier.

On the ground, rescue workers cleared a path for vehicles to reach the state capital, Gangtok, by removing debris from landslides that blocked a major highway. Authorities also restored power to the city. But villages in the north of the state remained largely cut off. Heavy rain hampered efforts to reach them.

An Indian border police force official says it evacuated 400 quake survivors to temporary shelters.

Indian authorities say the quake killed at least 35 people in Sikkim and injured more than 100 others. The quake also caused 13 deaths in the Indian states of Bihar and West Bengal. Many of the victims were killed by collapsing buildings and mudslides.

The earthquake also rattled Nepal and the Chinese region of Tibet, which border Sikkim. Nepalese authorities reported eight quake-related deaths, including three people killed by the collapse of a perimeter wall at the British embassy in Kathmandu. China's official Xinhua news agency says at least seven people were killed in southern Tibet.

Two strong aftershocks followed Sunday's quake and experts warned that more could follow. Many residents of Gangtok spent Sunday night and Monday morning in the streets, too afraid to stay in their homes.