Over 130 suspects linked to the Islamic State (IS) terror group have been operating in Sri Lanka, President Maithripala Sirisena said Friday, days after the terror outfit claimed responsibility for the Easter bombings that claimed the lives of 253 people.

The president said that several suspects have already been arrested following the Easter Sunday attacks, and the terror network will be completely eliminated from Sri Lanka.

Information is that around 130-140 ISIS suspects linked to the terror network are in Sri Lanka. Around 70 are arrested, we will arrest them all very soon ending this (terror)," Sirisena said.

Speaking further, the president said the Defence Secretary and Inspector General of Police had failed in their duties and that is why he called for their resignation.

He said that they had failed to shareprior information obtained by them over a possible terror attack in the country.

The president added that he and the entire Government will also take the full responsibility for the attacks.

Inspector General of Police Pujith Jaysundara and defence secretary Hemasiri Fernando have resigned from their posts over the security establishment's alleged failures which led to the attacks on three hotels and three churches on Sunday.

"The IGP has resigned. He has sent his resignation to the acting defense secretary. I'll nominate a new IGP soon," the president said.

The police chief's resignation came a day after the country's defence secretary Hemasiri Fernando handed over his resignation letter to the president.

Nine suicide bombers carried out aseries of devastating blasts that tore through three churches and three luxury hotels on Easter Sunday.

The Islamic State group has claimed responsibility for the attacks, but the government has blamed a local Islamist extremist group National Tawheed Jamath (NTJ) for the attacks.