"Terming them as cold-blooded and pre-plan-ned barbaric acts, he pointed out that these attacks were another grim reminder of the most serious challenge posed to entire humanity by terrorism in our region and the entire world," the government said in a statement.

The police sources told a news agency AFP that a "homemade" pipe bomb had been found late Sunday on a road leading towards the main terminal, which remains open with heavy security after Easter Sunday's deadly bomb attacks.

The death toll has rose to 207 people in deadly bomb blasts that ripped through high-end hotels and churches holding Easter services in Sri Lanka on Sunday. Ravinatha Aryasinha, secretary to the foreign ministry, told reporters there were 27 bodies of suspected foreign nationals in the Colombo National Hospital.