A strong 6.9 magnitude earthquake hit northeastern India and Nepal late Sunday, killing at least 18 people, damaging buildings and causing panic.

The epicenter of the quake was in the Indian state of Sikkim, about 60 kilometers northwest of the state capital, Gangtok. Sikkim's Chief Secretary said mudslides, building collapses and falling debris killed at least five people in the state and injured more than 50.

Indian authorities also reported quake-related deaths in Bihar and West Bengal states. The tremor was felt in the Indian capital, New Delhi, some 1,000 kilometers away and in the neighboring countries of Bangladesh and Bhutan.

The quake was followed by at least two strong aftershocks of magnitudes 6.1 and 5.3. Indian authorities warned more aftershocks are possible.

In Nepal, authorities reported at least five quake-related deaths. Three died in the capital, Kathmandu, when a brick wall toppled outside the British embassy. Another two died in a separate incident in the east.

A budget debate in Nepal's parliament was interrupted for 15 minutes while lawmakers fled the assembly hall as the building shook.

A reporter for VOA's Bangla service said the quake also caused cracks in some buildings in the capital of Bangladesh, Dhaka.

The full extent of India's earthquake damage was not immediately known, because the affected region is mountainous and sparsely populated. Electricity and phone lines also were cut off.

Indian Prime Minister Manmohan Singh called an emergency meeting of the National Disaster Management Authority to coordinate a response to the quake. The Indian air force also sent five planes to help with rescue and relief efforts.