All suspected plotters and those directly linked to Sri Lanka's Easter Sunday bombings have either been arrested or are dead, the country's acting police chief says.

Sri Lanka's $4.4 billion tourism industry is reeling from cancellations as travellers shun the sun and sand Indian Ocean island after multiple suicide bombings that killed over 250 people two weeks ago.

Sri Lanka's Catholic Church will televise a private Sunday mass after cancelling regular services over fears of a repeat of Easter's suicide bombings, even as police and troops tightened security.

Sri Lankan security officials warn that Islamist militants behind Easter Sunday's suicide bombings are planning imminent attacks and could be dressed in military uniforms.

Sri Lanka's Roman Catholic has condemned the Easter attacks as "an insult to humanity" as the tense and grief-stricken country marks a week since suicide bombers hit three churches and three luxury hotels.

Eleven Bangladeshi nationals, who used to work at a copper factory owned by Inshaf Ibrahim involved in the Shangri-La hotel bombing in Colombo on April 21, have been sent back by Sri Lanka.

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

Sri Lanka's top defence official resigns over security failures that led to the deadly Easter bombings, as Catholic churches suspended all services fearing further attacks.

Sri Lanka's government says it was suspending plans to grant citizens of 39 countries visa-free entry during the country's tourism low season after deadly Easter bombings that killed hundreds.

New Zealand Prime Minister Jacinda Ardern says she has not seen a shred of evidence to support claims the Easter Sunday massacres in Sri Lanka were a retaliation to the Christchurch mosque attacks.

As mourners buried the remains of Christian worshippers killed by the Easter Sunday suicide bomb attacks in Sri Lanka, hundreds of Muslim refugees fled Negombo on the country's west coast where communal tensions have flared in recent days.

Awami League leader Sheikh Fazlul Karim Selim’s grandson Zayan Chowdhury, who was killed in the series blasts in Sri Lanka on Easter Sunday, has been laid to rest in Dhaka.

Muslim brothers carried out two of the hotel suicide blasts in Sri Lanka on Easter Sunday, part of a wave of bombings that killed more than 320 people, police sources tell AFP.

The Islamic State group says it was behind a devastating string of suicide attacks against churches and hotels in Sri Lanka that killed more than 320 people on Easter Sunday.

Moshiul Haque Chowdhary, son-in-law of Awami League Presidium Member Sheikh Fazlul Karim Selim, has been taken to ICU of a hospital in Sri Lanka after surgeries.

The grandson of Awami League Presidium Member Sheikh Fazlul Karim Selim was killed in the series blasts that tore through churches and hotels in Sri Lanka on Easter Sunday.

Sri Lanka said yesterday it was invoking emergency powers in the aftermath of devastating bomb attacks on hotels and churches, blamed on militants with foreign links, in which 290 people were killed and nearly 500 wounded.

An explosion went off in a van near a church in Colombo, Sri Lanka, a day after scores were killed there, when bomb squad officials were trying to defuse the device, a police spokesman says.

Denmark's richest man Anders Holch Povlsen and his wife lose three of their four children in the Easter Sunday attacks in Sri Lanka, a spokesman for Povlsen's fashion firm says.

Awami League leader Sheikh Fazlul Karim Selim’s grandson Zayan Chowdhury has been killed in the series blasts in Sri Lanka.