At least eight workers from an Indian political party on a break after working on India's general election were among some 290 people killed in bomb attacks in Sri Lanka on Easter Sunday, a government official said.
Another two from a seven-member group from the party, the Janata Dal Secular (JDS), were missing.
The group was on an outing after voting took place on Thursday in India's general election in the southern state of Karnataka.
They were staying at the Shangri-La hotel in the Sri Lankan capital, Colombo. A suicide bomber attacked the hotel as guests sat down to a buffet breakfast.
"They were having breakfast on the second floor when the blast occurred," Rajath B, a family friend of one of the victims, KG Hanumantharayappa, told Reuters.
"Family in India got to know of the blast from the television."
The JDS is part of the ruling coalition in Karnataka state.
It is contesting the general election in an alliance with India's main opposition Congress party. The staggered general election began on April 11 and will end on May 19.
The party's leader, who is also Karnataka's chief minister, H D Kumaraswamy, said he was deeply pained by the loss.
"They were ... committed workers of our party and their death has brought immense sorrow to us," he said on Twitter.
Thirty-two foreigners were killed in the bomb attacks on churches holding Easter Sunday services and upmarket hotels.
No group has claimed responsibility but suspicion is focusing on Islamist militants.
At least seven Indians were killed, Indian officials said.