"Of the seven party workers who flew to Colombo, four have been declared dead and three missing. We are trying to ascertain their whereabouts through the Indian High Commission," the Chief Minister told reporters here.

The four who died in one of the blasts are Lakshmana Gowda Ramesh, K.M. Lakshminarayan, M. Rangappa and K.G. Hanumantharayappa.

The three missing workers are H. Shivukumar, A. Maregowda and N. Puttaraju.

"Chief Secretary T.M. Vijay Bhaskar is in touch with the High Commission through the External Affairs Ministry and the state's Resident Commissioner in New Delhi for more details" said the chief minister's office in a statement.

The party workers went to Sri Lanka on a holiday on Saturday after the first phase of polling on April 18 in the state's southern region, including Bengaluru.

"They were committed workers of our party and their deaths have brought sorrow to us," Kumaraswamy tweeted in Kannada.

"The members were staying in one of the hotels where the terror attacks took place. We are checking in which of the hotels they were staying," party spokesman Ramesh Babu told IANS.

Kumaraswamy said he knew the victims personally.