[4] At this location, the continental Indian and Eurasian plates converge with one another along a tectonic boundary beneath the mountainous region of northeast India near the Nepalese border.

Initial analyses also indicate a complex origin, with the perceived tremor likely being a result of two separate events occurring close together in time at similar focal depths.

Located at a shallow depth beneath the surface, the earthquake caused strong shaking in many areas adjacent to its epicenter reportedly lasting 30–40 seconds.

[14][better source needed] The strongest shaking occurred to the west in Gangtok and further south in Siliguri, although similar ground motions registering at VI (Strong) on the Modified Mercalli intensity scale were recorded in many smaller towns such as Mangan across elevated regions.

[3] Tremors were felt in Assam, Meghalaya, Tripura, parts of West Bengal, Bihar, Jharkhand, Uttar Pradesh, Rajasthan, Chandigarh and Delhi states of India.

The strong shaking caused significant building collapse and mudslides;[14] at least 111 people were confirmed killed and hundreds sustained injuries by the effects of the earthquake.

As the earthquake occurred during the monsoon season, heavy rain and landslides made rescue work increasingly difficult.

[23] In India, the total property damage is estimated to be around $22.3 billion USD, making it one of the costliest natural disasters in Indian history.

There, hundreds of homes sustained significant damage, and due to saturated soil from preceding heavy rains widespread mudslides impacted the region.

The quake was also felt in Dhaka, Rajshahi, Sylhet, Mymensingh, Barisal, Faridpur, Jessore, Khulna, Pabna, Bogra, Comilla, Noakhali, Chittagong and as far as Cox's Bazar.

[36] Prime Minister of Bhutan Jigmi Thinley updated in his status[37] as "Phone lines remains clogged reflecting our caring and close knit society.

[39] Indian former Prime Minister Dr. Manmohan Singh, on 19 September, announced ₹200,000 (US$2,300) as ex-gratia to a family member of those killed in the earthquake and ₹100,000 (US$1,200) for seriously injured.

Road opening parties succeeded in restoring communication along NH31A and work was continuing to repair the North Sikkim Highway to Mangan and Chungthang.

Fifteen helicopters were pressed into service to evacuate casualties and deploy rescue and relief columns in the affected areas of north and west Sikkim.

Several children from these camps even returned home on Tuesday and attended school On Monday, when weather improved, Special Forces personnel slithered from helicopters into affected villages.

Medical camps were set up and arrangements were made for casualty evacuation 21 engineering columns of the Army succeeded in restoring partial road connectivity to parts of north Sikkim on Tuesday.