The 7.3 magnitude earthquake's epicentre was in Kodari, Nepal and its effect was felt across north India, including Bihar.
The quake measuring 7.3 on the Richter scale shook Nepal, nearly three weeks after a more powerful temblor killed over 8,000 people in the Himalayan nation. The tremors were also felt in parts of northern and eastern India including Delhi, Patna, Lucknow, Guwahati, Bhubaneswar and Jaipur.
Prime Minister Narendra Modi held a meeting to take stock of the situation and directed authorities to be on high alert for rescue and relief operations.
Modi tweeted that he has "directed all concerned authorities to be on alert for carrying out rescue and relief operations, as required".
The home ministry said that it was in touch with state governments and put the NDRF on alert.
India Meteorological Department (IMD) director general L.S. Rathore said the earthquake's epicentre was 60 km east of Kathmandu.
After the quake, three major aftershocks were reported at close intervals.
"The first measured 5.4 on the Richter scale, the second was of 6.2 magnitude, and the last of 4.8," he said, adding the aftershocks would continue for weeks or months.
In Bihar, at least 8 people, including three children, were killed.
A labourer was killed when an under-construction wall collapsed in Danapur near Patna and a child in Siwan district, two children in Manigachi in Darbhanga district and a woman in Dumra of Sitamarhi district did in similar circumstances.
One person each died in Hajipur in Vaishali district, Nawada and Saran districts.
Over half a dozen girl students of a government middle school at Bihya in Bhojpur district were injured when they tried to rush out of their classroom.
Bihar Chief Minister Nitish Kumar, who directed officials concerned to assess the damage, however confirmed only six deaths, but said there was information on 15 and officers had been asked to verify these.
The Bihar government has also announced early summer vacation in schools. The vacation was supposed to start from May 16.
In Uttar Pradesh, two people were killed and half-a-dozen others injured.
A labourer was killed when an under-construction crematorium in Hamirpur collapsed while several other labourers were trapped in the rubble, while a girl was killed in Sambhal when her mud-and-thatch house caved in.
Two children were injured in a wall collapse in Ambedkar Nagar.
Chief Minister Akhilesh Yadav, who was attending an event at his official residence, was whisked away by his security personnel as soon as the tremors were felt.
West Bengal Chief Minister Mamata Banerjee urged people to stay calm in the wake of tremors felt in several parts of the state, including Murshidabad, Durgapur, Siliguri.
"Earthquake has once again struck many parts of our state and other parts of the country and abroad. I appeal to our people to maintain calm. Our government will provide all support," she posted on Facebook.
She said a round-the-clock control room had been opened at the state secretariat 'Nabanna' in nearby Howrah. The numbers are 1070 and 22143526.
Kolkata Metro as well as the metro services in Delhi were halted due to the tremors, while the cell phone services were also reportedly disrupted in several stretches.
Mild tremors were also felt in various parts of Odisha, including Bhubaneswar, Cuttack , Ganjam, Kendrapada and Rourkela.
The temblor caused panic among people in the national capital.
"I was with my client at home when the quake occurred. We all ran outside the building and saw many others rushing out of their houses after feeling the tremors that lasted at least for 30-45 seconds," Uttam Dutt, a lawyer, told IANS.