The high-intensity quake was followed by two after-shocks and had its epicentre on the Sikkim-Nepal border.
Extensive damages to several buildings were reported in various parts of Sikkim due to the earthquake, whose epicentre was said to be was located at Mangan and Sakyong areas, over 50 km from Gangtok on Sikkim-Nepal border. The earthquake is being described as the biggest in 20 years in the northeast.
The number of those injured in the earthquake crossed 200 as reports came in here from different areas.
Sikkim has been cut off from the rest of the country with the national highway 31-A blocked in at least eight places following heavy mudslides, said G. Anandan, district magistrate, Sikkim East.
As many as 25 concrete bridges were damaged between Siliguri and Gangtok on the 120 km long national highway 31-A, he said.
The Sikkim secretariat also developed cracks, he added.
More updates on Sikkim earthquake:
# Road from Pegong to Chungthang tehsil washed away due to landslide.
# NDRF personnel are waiting for the highway to be cleared.
# Sikkim govt confirms 18 deaths. Rescue team of state has reached Mangan area of north Sikkim but they are yet to get input from Chungthang.
# Big landslides all over NH 31A - the lifeline of Sikkim. NDRF forces are still stranded in Siliguri.
# A herculean rescue operation begins as NDRF and Army battalions reach Sikkim.
# Missing vehicle including Army personnel found, all safe: Report
# 10 army Combat Engineers Columns deployed for opening major roadblocks on Siliguri-Gangtok.
# No casualties reported so far from Bhutan but building damages, road blocks and few minor injuries reported.
Quake kills six in Bihar
At least six people were killed and dozens injured in several parts of Bihar, police said Monday.
Two people died in Nawada, and one in Darbhanga, Nalanda, Bhagalpur and Patna each, Additional Director General of Police Rajvardhan Sharma said.
Chief Minister Nitish Kumar has announced Rs.1.5 lakh compensation for the kin of each of the deceased.
Quake kills six in West Bengal
At least six people were killed and over 200 injured in northern districts in West Bengal.
Two people died in Siliguri, three in Darjeeling and one in Jalpaiguri district, police said.
Many buildings developed cracks and the neighbouring Himalayan state of Sikkim was cut-off from north Bengal by landslides triggered by the tremors in Darjeeling's Kalimpong and Kurseong hill sub-divisions.
Quake jolts north India
Tremors were felt in Assam, Meghalaya, Tripura, parts of West Bengal, Bihar, Jharkhand, Uttar Pradesh, Rajasthan, Chandigarh and Delhi, according to Indian Meteorological Department.
One of the two persons was killed at Singtham in East Sikkim district and another died just outside Singtham, Sikkim Chief Secretary Karma Gyatso said.
According to officials, two buildings of the Indo Tibetan Border Police (ITBP) collapsed in Pegong area though there was no immediate report of any casualty.
Three after shocks of 5.7, 5.3 and 4.6 magnitude on the Richter Scale were felt in the region within 30 minutes of the first quake.
Two teams of the National Disaster Response Force - five each from Delhi and Kolkata - are being sent to assist in the relief and rescue operations, R K Srivastava, Joint Secretary, Disaster Management, in the Home Ministry, said.
Reports said that phone lines got congested in Bengal and parts of Sikkim faced immediate power cut. However, no cases of any immediate damage and casualty have been reported from any parts of the country so far.
Many people were injured, power supply was disrupted in parts of northern West Bengal and houses developed cracks as a powerul quake, epicentred in adjoining Sikkim, rocked the region.
Reports said that phone lines got congested in Bengal and parts of Sikkim faced immediate power cut. However, no cases of any immediate damage and casualty have been reported from any parts of the country so far.
Many people were injured, power supply was disrupted in parts of northern West Bengal and houses developed cracks as a powerul quake, epicentred in adjoining Sikkim, rocked the region.
North Bengal Affairs Minister Gautam Deb said the quake triggered landslides in Kalimpong and Kurseong sub-divisions while several patients in a nursing home in Siliguri sub-division of Darjeeling district were injured.
5 killed in Nepal
At least five people were killed when a strong 6.8 magnitude earthquake jolted various parts of this Himalayan country on Sunday.
Three people were killed when a high brick wall of the British Embassy here collapsed due to earthquake.
A man and his daughter and another pedestrian died after the wall of the Embassy at Lainchaur collapsed on them, according to sources at the Sorhakhutte Police Station.
Two more people killed in Dsaran municipality in eastern Nepal which was close to the epicentre of the quake.
At least 27 people in the capital were injured when they panicked and ran outside after the quake.
The Indian Embassy premises which is adjoining to the British Embassy compound did not suffer any damage, according to a mission spokesperson.
There was continuous rain in Kathmandu during the tremor and the foundation of the wall might have been weakened due to the rain and finally collapsed during the tremor, eye-witnesses said.