An extremist leader considered a central figure in Sri Lanka's Easter suicide bombings died in the attacks, the president said Friday as the police chief became the latest figure to quit over the failure to prevent the massacre.

Sri Lanka's top police official, Inspector General of Police Pujith Jayasundara, has resigned over failures that led to the deadly Easter bomb attacks, the country's president said Friday.

Corrects 8th paragraph, to say government suspending plans to allow visa-free entry from May 1, instead of suspending visas as sent. Herewith corrected repetition

by Amal Jayasinghe in Colombo and Ammu Kannampilly in Batticaloa

Sri Lankan security forces detained 18 new suspects in the Easter bombings that killed more than 350 people, as the government admitted Wednesday that "major" intelligence lapses had led to a failure to prevent the attacks. 

Sri Lanka began a day of national mourning Tuesday with three minutes of silence to honour more than 300 people killed in suicide bomb blasts that have been blamed on a local Islamist group.

Sri Lankan authorities blocked most social media after Easter Sunday attacks killed more than 200 people, with officials saying the temporary move was meant to curtail the spread of false information and ease tensions.

Top Muslim leaders in Sri Lanka on Monday demanded "maximum punishment" for the perpetrators of suicide bomb attacks on Christian churches and luxury hotels in the country that left at least 290 dead.

The comments came as the government refused to give details of at least 24 people arrested over the Easter Sunday attacks for fear of fanning ethnic tensions. Scores of Christians were among the dead.

The Sri Lankan government believes a local Islamist extremist group called the National Thowheeth Jama'ath (NTJ) was behind the deadly suicide bomb attacks that killed nearly 300 people, government spokesman Rajitha Senaratne said Monday.

Religious and world leaders have condemned a series of blasts in Sri Lanka that killed at least 290 people on Sunday, including dozens of foreigners with British, Dutch and American citizens believed to be among them.

Sri Lanka's parliament will meet under tight security Wednesday, after the top court ruled its dissolution illegal and opened the door to a vote on which of two rival prime ministers has the support to rule.