Sri Lankan officials have said Sunday’s Easter bombings were orchestrated with the support of an international network.
Authorities have accused little-known local jihadist group, National Towheed Jamath, although no-one has yet admitted carrying out the attacks.
The death toll from the attack has soared to 290 with another 500 injured after multiple suicide blasts.
“We do not believe these attacks were carried out by a group of people who were confined to this country,” cabinet spokesman Rajitha Senaratne said.
“There was an international network without which these attacks could not have succeeded.”
“The intelligence reports [indicate] that foreign terrorist organisations are behind the local terrorists. Therefore, the president is to seek the assistance of the foreign countries,” his office said.
On Sunday, Sri Lankan Prime Minister Ranil Wickremesinghe said security services had been “aware of information” of possible attacks but that the information had not been acted upon.
A national emergency has been declared to start on Monday midnight while Tuesday has been set for national mourning.