New Delhi: Seventy out of the 140 Islamic State suspects behind the devastating Easter Sunday attacks in Sri Lanka have been held, said President  Maithripala Sirisena on Friday and assured that the remaining suspects will be caught soon.

While addressing mediapersons at a press conference Sirisena vowed to wipe out global terror network from the island nation.

He said that there were as many as 140 Islamic State suspects in the country and 70 of them have already been held and 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 was quoted as saying.

He added that the country will also take assistance from other nations to fight the terror groups.

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.

Sirisena's government has come under strong criticism, for its failure to prevent the attacks despite intelligence warnings indicating the threat of bombings.

The government also on Thursday night substantially cut down the death toll from 359 to about 253, citing calculation errors in the previous figure.

Dr Anil Jasinghe, the Director General of the Health Services, said the larger death toll was released as a result of a calculation error.

"The approximate total of the dead would be 253 and not 359 as reported in media," he said.

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.