Colombo, Sri Lanka (CNN) Sri Lankan intelligence services believe the Easter Sunday suicide bombers had “very clear” links to ISIS, the country’s president told CNN Monday.

President Maithripala Sirisena said the terror group had provided training to the perpetrators of last week’s attacks, and that links between ISIS and extremists in Sri Lanka could be traced back 15 years.

But Sirisena rejected claims that he should resign in the face of the catastrophic intelligence failures in the runup to the attacks, which killed more than 250 people and injured at least 500. Instead, he blamed officials and ministers in his government for failing to act on warnings.

Secretary of Defense Hemesiri Fernando and the Inspector General of Police Pujith Jayasundara had been “careless, negligent and irresponsible in executing their duties” for “not thinking that an incident of this nature would actually occur,” the President said. Fernando resigned last week.

Sirisena said he had “not been updated or notified with the information that they received about the possibility of such a severe attack on our soil.”

The President admitted that he was abroad “for a personal holiday” when intelligence memos warning of a potential terrorist act were sent to Sri Lankan defense ministry and police chiefs.

Sirisena also hit back at criticism that a political rift with his Prime Minister had created a governmental void which paved the way for such terrorist attacks to take place. “When it comes to national security, there are no party differences, religious differences or racial differences between us as Sri Lankans,” he said.

“At present, myself, the Prime Minister, the government, we are all working as one, to ensure that the country is safeguarded,” he said.

Source: CNN

-Agencies