NEW DELHI: The death toll of Indian nationals in Sri Lanka’s deadly weekend serial blasts has reached eight with the Indian high commission in Colombo confirming the deaths of five people on Monday.

This was in addition to the deaths of three people confirmed on Sunday.

“Sri Lankan Foreign Ministry has confirmed the death of one more individual - H Shivakumar - in the blasts yesterday (Sunday), taking the total number of Indian deaths in the tragedy to 8 till now," the Indian high commission said in a Twitter post.

Meanwhile, Karnataka chief minister H.D Kumaraswamy said in a Twitter post that

four out of seven members belonging to his Janata Dal (Secular) party had been killed in the blasts while the whereabouts of three others, H.Shivu Kumar,A.Maregowda and H.Puttaraju were not known.

The rise in the number of Indian casualties came on a day India put its coast guard on high alert after the Sri Lankan government said it believed a local Islamist extremist group -- the National Thowheeth Jama’ath (NTJ) -- was behind the Easter Sunday attacks. The NTJ is suspected to have a presence in Tamil Nadu and the alert is aimed to ensure members of the group do not escape to India, a person familiar with the development said.