KEY POINTS:

• At least 207 people have been killed and 450 more injured in a wave of suicide bombings targeting churches and hotels at Easter in Sri Lanka
• About 30 foreigners are among the victims including Americans and Brits; Kiwis tell of being at the centre of terror
• No one has claimed responsibility for the attacks but the Sri Lankan Government has blamed religious extremists
• Thirteen people have been reported to have been arrested so far
• Sri Lankan authorities have blocked most social media services in the country, including Facebook, YouTube, WhatsApp and Instagram.

A bomb was found and safely destroyed at Sri Lanka's main airport just hours after co-ordinated attacks killed 207 people in explosions at churches and five-star hotels on Easter Sunday.

Eight blasts ripped through landmarks around the capital Colombo, and on Sri Lanka's east coast, targeting Christians, hotel guests and foreign tourists.

More than 450 people were wounded and at least 27 foreigners - including five British citizens - are among the dead. There are 115 Kiwis registered in Sri Lanka but so far no fatalities have been reported - several have described being at the centre of the terror.

Huge queues are seen at Katunayake airport (BIA) as passengers are subject to extra security checks in the wake of coordinated explosions in the island. #EasterAttackSL #SriLanka pic.twitter.com/VnSkgjwwjZ

— Kavinthan s (@Kavinthans) April 21, 2019

A six-foot pipe bomb was later found by air force personnel on a routine patrol at the country's main airport Bandaranaike International, also known as Katunayake Airport or Colombo International.

"A PVC pipe which was six feet in length containing explosives in it was discovered," Air Force Spokesman Gihan Seneviratne told the Sri Lankan Sunday Times.

He said the bomb device was discovered by Air Force personnel on a routine patrol and was disposed by the Explosives Ordinance Disposal Unit of the Air Force in a controlled area.

The airport was put "on lockdown" while the security forces examined and detonated the device, according to reports from the scene.

It comes after six bombs went off in quick succession before another two blasts two hours later in Sri Lanka's worst violence since the end of its decades-long civil war in 2009.

The suicide bombers struck churches and hotels in Sri Lanka in a highly coordinated attack, killing at least 207 people and injuring 450 on Easter Sunday.

Dead Bodies are carried away for identification in front of the St Anthony's Church where one explosion took place in Kochchikade, Colombo. Photo / Getty

No group has yet claimed responsibility for the attacks, the worst violence in Sri Lanka since the end of the civil war a decade ago. Thirteen people have been arrested, police said, and three police officers were killed in a raid on a house as they attempted to interrogate an individual.

At least 27 of the people killed were foreigners, including American, British, Chinese, Indian, Turkish, Dutch and Portuguese nationals.

Prime Minister Ranil Wickremasinghe told reporters that elements of the government had prior intelligence about the attacks. He did not elaborate.

"Information was there," he said at a news conference. "That is a matter that we need to look into."

Wickremasinghe said the suspects were "local."

New Zealand Prime Minister Jacinda Ardern has described co-ordinated bomb attacks on Sri Lankan churches and hotels as "devastating" and extended New Zealand's condolences to the grieving nation.

Blasts ripped through three churches in the cities of Colombo, Negombo and Batticaloa at approximately 8.45am local time yesterday as Easter worshippers were gathering for services, police said. Bombers also struck three hotels and a banquet hall in Colombo, the nation's capital.

Ruwan Wijewardene, Sri Lanka's minister for defence, said the attacks were carried out by suicide bombers. The explosions at the churches and hotels occurred between 8.45 and 9.30 am local time.

An inside view of the St. Anthony's Shrine after an explosion. A string of blasts ripped through high-end hotels and churches as worshippers attended Easter services. Photo / Getty

An eighth blast occurred later at a home under a flyover in the city.

Sri Lanka is a predominantly Buddhist nation but is also home to significant Hindu, Muslim and Christian communities. Easter is the holiest day of the Christian calendar.

At least 66 people were killed in Colombo and 104 in the nearby town of Negombo, officials said. Twenty-eight people were killed in the eastern city of Batticaloa.

Three police officers were killed in a "scuffle" at a house in the Demtagoda area of Colombo, police said. They had gone to the house to interrogate an individual.

At least 11 of the dead at National Hospital in Colombo were foreigners, according to the foreign ministry.

US Secretary of State Mike Pompeo condemned the attacks "in the strongest terms."

"Attacks on innocent people gathering in a place of worship or enjoying a holiday meal are affronts to the universal values and freedoms that we hold dear, and demonstrate yet again the brutal nature of radical terrorists whose sole aim is to threaten peace and security," he said in a statement.

The unidentified bodies of 25 people believed to be foreigners were at the Colombo Judicial Medical Officer's Mortuary.

Images from inside St Anthony's Kochchikade, the largest Roman Catholic congregation in Colombo, showed shattered wooden pews and floors stained with blood.

Deadly blasts also struck St Sebastian's Church in Negombo, a beach town about 30km north of the capital, and Zion Church in Batticaloa.

Two people at the Shangri-La Hotel in Colombo described a powerful explosion that made the ground shake just before 9am. Photos showed broken windows and shattered glass on a street next to the hotel.

The Shangri-La hotel's second-floor restaurant was gutted in one of several blasts which hit Sri Lanka on Easter Sunday.

Follow live updates here: https://t.co/x2yZrXODO1 pic.twitter.com/5NWNSJOdJL

— Sky News (@SkyNews) April 21, 2019

At the Cinnamon Grand Hotel, the blast took place in a restaurant on the ground floor, the hotel wrote on Twitter. It said the injured were promptly evacuated.

Explosions were also reported at the Kingsbury Hotel and the New Tropical Inn.

Sri Lankan authorities announced a nationwide curfew, effective immediately. They also blocked Facebook and the messaging application WhatsApp to stop the spread of false and inflammatory messages.

Wickremesinghe, the Prime Minister, condemned "the cowardly attacks on our people today" and urged the country to remain "united and strong."

Graphic / NZ Herald

Harsh de Silva, a government minister wrote on Twitter that he had seen "horrible scenes" after the explosions and that there were "many casualties including foreigners." He urged people to stay indoors.

Sri Lanka, a popular tourism destination, has been largely peaceful since the end of its long-running civil war a decade ago. The country has seen intermittent conflict between religious groups, but nothing remotely on the scale of yesterday's attacks.

The bombings were the worst violence to hit Colombo since 1996, when a blast at the country's Central Bank killed nearly 100 people. That attack was carried out by the Liberation Tigers of Tamil Eelam, or Tamil Tigers, which waged a war for a separate Tamil homeland in Sri Lanka's north for more than 30 years.

Messages of condolence and condemnation poured in from around the world.

Two senior intelligence officials told The Daily Beast that a Sri Lankan police official had alerted security officials ten days ago about a threat on churches, though it remains unseen what, if any, safety measures were taken to protect worshipers https://t.co/0CopJ0Bh69

— The Daily Beast (@thedailybeast) April 21, 2019

US President Donald Trump tweeted: "The United States offers heartfelt condolences to the great people of Sri Lanka. We stand ready to help!"

Pope Francis during his Easter address called the attacks "horrendous" and expressed "heartfelt closeness to the Christian community, attacked while gathered in prayer, and to all the victims of such a cruel act of violence."

"I entrust to the Lord all who so tragically died, and I pray for the wounded and all those who suffer because of this traumatic event," Francis said.

India, Sri Lanka's neighbour, strongly condemned what it called a "ghastly and heinous act" and said it stood with the people of Sri Lanka "in this hour of grief."

The Church of England posted a prayer for the people of Sri Lanka on Twitter.