Sri Lanka’s Defence Secretary Hemasiri Fernando resigned from his post on Thursday, days after a series of devastating suicide attacks that tore through three churches and three luxury hotels on Easter Sunday, killing nearly 360 people.

President Maithripala Sirisena had asked Defence Secretary Fernando and Inspector General of Police Pujith Jayasundara to quit after their failure to prevent the blasts despite having prior intelligence.

Fernando handed over his resignation letter Thursday on a request made by President Sirisena, Colombo Gazette reported.

Meanwhile, Field Marshal Sarath Fonseka said that the Islamist extremist group behind the deadly Easter Sunday blasts in Sri Lanka would have been planning the suicide attacks for “at least 7 to 8 years” and could be led by someone having the calibre of slain LTTE supremo Velupillai Prabakaran.

Speaking during the emergency debate in Parliament, Fonseka, who led the Sri Lankan military that vanquished the Liberation Tigers of Tamil Eelam in 2009, was quoted by the media as saying that the Easter attacks were a long planned one.

“It took 12 years for the LTTE to carry out a suicide attack on the then Defence Minister Ranjan Wijeyaratne. Therefore, these people must have planned the recent attack at least seven to eight years ago,” he said on Wednesday.

“The LTTE’s terrorism was markedly different as it was an organisation fighting to divide the country. Its motives were political, whereas this group is pushing a religious agenda,” the 68-year-old Field Marshal said, apparently referring to the little-known National Thowheed Jamath (NTJ).

Authorities have accused the NTJ of carrying out the devastating blasts that tore through three churches and three luxury hotels on the Easter Sunday, killing over 350 people, including 11 Indians and injuring nearly 500 others.

Daily Mirror quoted Fonseka as saying that the group that carried out Sri Lanka’s worst terror attack might have already established a leader of Prabakaran’s calibre.

Prabhakaran is generally credited with perfecting the recruitment and use of suicide bomber units of Tamil Tigers against the Lankan military and political leaders.

On Tuesday, the Islamic State said it had carried out the attacks, and released a propaganda video of men it says were the bombers, pledging allegiance to the group chief Abu Bakr al-Baghdadi.

In the video, all but one of the seven men can be seen with their faces covered. Three of them were holding knives. The bearded man with his face uncovered has been named as the suspected ringleader, Sri Lankan Islamist preacher Zahran Hashim.

It is unclear if Hashim was among the suicide bombers.

Fonseka also criticised the government for ignoring the advance intelligence on the attack.

“I regret that the intelligence reports on the recent attack were ignored,” he was quoted as saying by Ceylon Today.

Fonseka, described as Sri Lanka’s most successful general, also criticised the government for not consulting him earlier in the aftermath of the massive attack.

“I was given a chance to meet the Prime Minister 48 hours after the terror attack. I did not earn the title Field Marshal for selling snacks in Galle Face,” he said, referring to the ocean-side urban park in Colombo.

“There is no member in this Government who has more knowledge than I have with regard to national security related matters. If there is any such person, I will give this title to him. This Government never uses our knowledge. I do not need any positions. Just utilise the knowledge of people like me to ensure national security,” he said in Parliament.

He also said the Easter Sunday tragedy was the result of a “weak” government and faulted President Maithripala Sirisena, Prime Minister Ranil Wickremesinghe and defence officials for the country’s worst terror attacks.

Nine suicide bombers, believed to be members of local Islamist extremist group called National Thowheed Jamath (NTJ), carried out the devastating blasts that killed 359 people and wounded more than 500 others.