Sri Lankan President Maithripala Sirisena on Monday named a new police chief and appointed a new advisor to the defense ministry after the Apr. 21 Easter Sunday attacks left 253 people dead.

"Senior DIG (Deputy Inspector General) C. D. Wickremeratne (the second-in-command in the police force) has been appointed as the acting IGP (inspector general of police) and former IGP N.K. Illangakoon has been appointed as an advisor to the defense ministry," a statement by the president's office said.

Sirisena last week blamed intelligence failures for the devastating Easter bombings at churches and luxury hotels, and promised a major shakeup in the country’s security apparatus.

The president had sought resignations from Defense Secretary Hemasiri Fernando and IGP Pujith Jayasundara amid growing public outrage over the government’s apparent failure to act on intelligence reports indicating that Islamist groups were planning to target churches in the Buddhist-majority country.

The defense secretary resigned last Thursday, saying he had systematically "disseminated the intelligence information received about the attacks on the competent officials and departments" and that he had complied with his duties.

Jayasundara was yet to announce his resignation, even as the president named the new police chief. It was not immediately clear if he has resigned or been sent on compulsory leave.

The defense secretary occupies the third position in the chain of command of office after the country's president, who also holds the post of defense minister, and who is followed by the Deputy Minister of Defense, Ruwan Wijewardene.

Sri Lanka has been in a state of emergency since the attacks claimed by Islamic State global terror network, as the government has deployed thousands of troops to round up any remaining Islamist extremists.

Scores of suspects have been arrested since the attacks and some 16 people, six of them minors, were killed in a clash between the security forces and an armed group suspected of having a hand in the Easter attacks.

President Sirisena on Thursday said that there were as many as 140 Islamic State suspects in the country and 70 of them had already been apprehended.

There have been a number of attacks against religious minorities in the past on the island, where Christians make up 7.4 percent of the population, with Buddhists accounting for 70.2 percent.

There are 12.6 percent Hindus and 9.7 percent Muslims, according to the 2011 census.

In 2018, the government declared a state of emergency after violence erupted between Muslims and the majority Sinhalese Buddhists leading to two deaths and dozens of arrests.

The recent bombings were the worst attacks since the Sri Lankan civil war between Tamil guerrillas and government ended in 2009.

The 26-year-old conflict claimed the lives of tens of thousands of civilians, according to data from the United Nations.