Sri Lanka has invoked emergency powers beginning from midnight (local time) yesterday as security forces probe Sunday's devastating series of suicide attacks on hotels and churches.

The death toll has soared close to 300, with fears that it could rise. Colombo remained tense yesterday as blasts from bombs being detonated by local disposal units were mistaken for fresh attacks.

It remains unclear who is responsible for the attacks but a government spokesman has suggested a local Islamic extremist group, the National Thowheeth Jama'ath, could be involved. He said investigators were trying to determine if the group had "international support".

A second dusk-to-dawn curfew was also imposed on the island even as tourists scrambled to fly out of Colombo. President Maithripala Sirisena said today will be observed as a day of national mourning.

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