Sri Lanka: PM warns of 'sleeper cells'

Sri Lankan Prime Minister Ranil Wickremesinghe, who has been dealing with the aftermath of Easter Sunday attack, warned on Thursday of "sleeper cells" that might launch more attacks in the island nation.

"The danger has come down drastically, (but) we do have to pick up some more sleepers, which we will do in the next few days," Wickremesinghe told CNN.

"Police and security forces are rounding up those involved, but they're also rounding up the sleepers, those used on second and third rounds (of attacks)," he added.

Amid intense criticism over Sri Lankan government's inaction in curbing the massacre, President Maithripala Sirisena has asked Defence Secretary Hemasiri Fernando and Inspector General of Police Pujith Jayasundara to resign following reports of mishandling of intelligence reports.

On April 21, eight explosions rattled Sri Lankan cities of Colombo, Negombo, Kochchikede and Batticaloa as the Christian community celebrated Easter Sunday. At least 359 people were killed and over 500 others were injured in the serial blasts.

The casualties included 39 foreign nationals, including 10 Indians.