Sri Lankan President Maherpala Seressina has been killed in the attacks that killed 359 people and wounded 500 others, police chief Bugit Jayasundara said on Tuesday.

Seressina said in a press statement Friday that the intelligence services told him that Hashim was killed during the attack on the Shangri-La Hotel in the capital. Authorities believe the dead man is behind the nine attacks.

Hashem appeared in a video broadcast by the Islamic state organization after the latter claimed responsibility for the attacks, but the place of Hashem, who leads the group "National Tawheed" has remained unknown.

Investigations and arrests
The head of the country said that the authorities arrested seven elements of the state organization, and seeks to arrest 140 people linked to the organization, and stressed that the government must bear responsibility for the attacks, and explained that the police chief informed him that he will resign, as announced by the Undersecretary of Defense resignation.

Authorities sought security and army to protect vital places after Sunday's attacks (Reuters)

Prime Minister Ranil Wickremesinghe said investigations into the "Bloody Easter" bombings were making significant progress. In an interview with Al Jazeera, he confirmed the arrest of dozens and the discovery of two groups involved in the operations. Among those detained was a copper factory manager who helped the attackers prepare explosives and buy empty cartridges sold by the army in the scrap market.

The authorities announced the involvement of a group of nine "suicide bombers" from wealthy families, including a woman, in the implementation of the attacks, and officials said that the security services arrested the second man of the National Tawheed.

One of the suspects in Sunday's attacks had been investigated by the Australian authorities for being linked to a key suspect recruiting fighters for the state organization, the German news agency quoted Sri Lankan media as saying.

Security failure
Wickremesinghe acknowledged the failure of the security and intelligence services to gather information on the attacks, and said even the police and the Ministry of Health had provided conflicting data on the number of victims of the attacks.

He acknowledged the occurrence of some attacks and extremist sermons that affected Muslims after Easter attacks, and denied in his interview with the island the occurrence of mass violence against Muslims, stressing that the situation under control.

Authorities have called on all mosques and churches not to pray Friday and Sunday. She attributed the warning to the General Intelligence on the possibility of attacks on places of worship using car bombs, and the Associated Press quoted the Prime Minister that there are suspects in the attack are still fugitives and may have explosives.