Regarding the investigations, he said investigators had made good progress in identifying the culprits, and it would take more time. "There is also news coming in from Cairo that the ISIS has claimed responsibility."

All the 40 suspects who have been taken into custody are Sri Lankan citizens, he said. "It is possible it could have been because of the Christchurch attack."

Concerning the reports that the Sri Lankan intelligence had received terror attack warnings about 10 days ago yet relevant institutions had failed to act to prevent the attacks, Wickremasinghe said President Maithripala Sirisena has launched an inquiry as to why the intelligence did not reach the prime minister's office.

"The government will continue its policy of having unity in the country and having religious groups getting together while cracking down on global terrorism," the prime minister said.

In an exclusive interview with Xinhua on Tuesday, Sri Lankan Minister of Tourism Development and Christian Religious Affairs John Amaratunga said that the multiple blasts which claimed more than 300 lives on Sunday was "internationally oriented," and the situation here was gradually returning to normal.

"We have had our own problems 10 years ago, but this time it is an international movement that has sought to dislocate the Sri Lankan economy particularly by attacking the tourist hotels and also to create unrest in the country by attacking the Christian or Catholic churches," he said.

He asked global visitors, including Chinese visitors, not to be discouraged by the incident, and said Sri Lanka will "bounce back" in about one month to be "a safe place for all tourists to come and enjoy peace."

At the national blood donation center, Deputy Director Feels Saranajeewa told Xinhua that people swarmed into the center after the terrorist attacks occurred. "There was a big crowd. When the people heard about this they came and tried to donate blood," he said.