Sri Lankan President Maithripala Sirisena on Friday said that there were as many as 140 Islamic State suspects in the country and 70 of them have already been held after the Easter Sunday bombings.
At a press conference here, Sirisena vowed to wipe out the global terror network from the island nation as the remaining IS suspects would be detained "very soon", reports Efe news.
"I will stamp out IS from Sri Lanka. Our police and security forces are capable of achieving this," he said, adding that the country would also take assistance from other nations to fight the terror group.
Sirisena said the person who led the attacks on Sunday had been identified as Mohamed Zahran, who died in a blast in the Shangri-La Hotel in Colombo.
He said he belonged to local Islamist outfit National Thowheed Jamaath, which was earlier blamed for the attacks.
Sirisena blamed security officials and promised action against those officials who "neglected" their duties.
He also announced that Inspector General of Police (IGP) Pujith Jayasundara, who was asked to quit over mishandling intelligence reports ahead of the bombings, will resign later in the day,
While reiterating that both Jayasundara and the outgoing Defence Secretary Hemasiri Fernando, who resigned on Thursday, did not fulfil their responsibilities, the President said there would be "a total reorganization (of) the security establishment in the days to come".
The President warned of a close relationship between extremism and drug-trafficking, which the government has tried to tackle through several controversial measures in recent months.
Sirisena's government has drawn flak for its failure to prevent the attacks despite intelligence warnings indicating the threat of bombings.
The country has been in a state of emergency after suicide bombers hit three luxury hotels in Colombo and three churches around the country during Easter services in a series of coordinated attacks.
A few hours later, a seventh blast rocked a small hotel about 12 km south of the capital while an eighth explosion took place at a residential compound in Dematagoda in Colombo.
Police have said at least nine suicide bombers loaded with powerful explosives carried out the attacks.
On Thursday, Sri Lanka reduced the death toll in the Easter Sunday bombings to 253 - almost a hundred less than previously feared.
The revised toll came after the authorities said there was an error in calculating the number of victims.