Crime scene officials inspect the explosion area at Shangri-La hotel in Colombo on Sunday. Dinuka Liyanawatte / Reuters
Hospital sources also said Japanese citizens were among those injured by the bombs which ripped through high-end hotels and churches holding Easter services.
Here is a summary of the reactions:
Britain: 'Stand together'
British Prime Minister Theresa May described the attacks as "truly appalling."
"The acts of violence against churches and hotels in Sri Lanka are truly appalling, and my deepest sympathies go out to all of those affected at this tragic time," she tweeted.
"We must stand together to make sure that no one should ever have to practise their faith in fear."
Trump: 'Ready to help'
US President Donald Trump tweeted: "Heartfelt condolences from the people of the United States to the people of Sri Lanka on the horrible terrorist attacks on churches and hotels," he tweeted. "We stand ready to help!"
The Netherlands: 'Terrible reports'
"Terrible reports from Sri Lanka about bloody attacks on hotels and churches on this Easter Sunday," Dutch Prime Minister Mark Rutte tweeted after initial news of the attacks.
"Thoughts are with the victims and their relatives."
Pope: 'Cruel violence'
Pope Francis expressed his sadness over the attacks during his traditional Easter address at the Vatican.
"I want to express my affectionate closeness with the Christian community, attacked while it was at prayer, and to all the victims of such cruel violence," he said.
The Catholic Church in Jerusalem had said in an earlier statement: "We pray for the souls of the victims and ask for speedy recovery of the injured, and ask God to inspire the terrorists to repent of their killing and intimidation."
Australia: 'Terrorist attack'
Prime Minister Scott Morrison said in a statement: "To the beautiful people of Sri Lanka, Australia sends its heartfelt sympathies and our prayers and our support — and our offer to do whatever we can to support you in this terrible time of need.
"At this time as Easter Sunday draws to a conclusion here in Australia, our heart goes out to those Christians and all of those other innocents who have been slaughtered today in this horrific terrorist attack."
New Zealand: 'Devastating'
A month after dozens of Muslims were killed in a shooting at two mosques in Christchurch, New Zealand Prime Minister Jacinda Ardern described the Sri Lanka attack as "devastating."
"New Zealand condemns all acts of terrorism, and our resolve has only been strengthened by the attack on our soil on the 15th of March. To see an attack in Sri Lanka while people were in churches and at hotels is devastating.
"New Zealand rejects all forms of extremism and stands for freedom of religion and the right to worship safely. Collectively we must find the will and the answers to end such violence."
Pakistan's leader Imran Khan offered his "profound condolences" to Sri Lanka.
"Strongly condemn the horrific terrorist attack in Sri Lanka on Easter Sunday resulting in precious lives lost & hundreds injured," he tweeted.
"My profound condolences go to our Sri Lankan brethren. Pakistan stands in complete solidarity with Sri Lanka in their hour of grief."
India: 'Cold blooded'
Narendra Modi, the leader of neighbouring India, condemmned the "serial terrorist attacks" in a government statement.
"Terming them as cold-blooded and pre-planned barbaric acts, he pointed out that these attacks were another grim reminder of the most serious challenge posed to the entire humanity by terrorism in our region and the entire world," the statement added.
"There is no place for such barbarism in our region," he tweeted earlier.
EU: 'Sad day for the world'
EU commission chief Jean-Claude Juncker expressed his "horror and sadness" at the blasts, while EU foreign policy chief Federica Mogherini said the attacks marked "a truly sad day for the country and for the world".
"Such acts of violence on this holy day are acts of violence against all beliefs and denominations, and against all those who value the freedom of religion and the choice to worship," she added in a statement.
France: 'Odious acts'
"We strongly condemn these odious acts," French President Emmanuel Macron wrote on Twitter.
"Full solidarity with the Sri Lanka people and our thoughts for all those close to the victims this Easter."
Germany: 'Malicious attack'
German Chancellor Angela Merkel said "religious hate and intolerance that have showed themselves in such a terrible way today must not win."
"It is shocking that people who gathered to celebrate Easter together were consciously targeted in this malicious attack," Merkel said in a statement published by a spokeswoman on Twitter.
Russia: 'Cynical crime'
"I would like to reassert that Russia has been and remains a reliable partner of Sri Lanka in combating the threat of international terrorism," Vladimir Putin said in a Kremlin statement.
"I expect that the masterminds and perpetrators of such a heinous and cynical crime committed in the midst of Easter celebrations will get the punishment they deserve."Agence France-Presse
'Terrorists are those who betray worshippers in their places of worship, plant fear in their hearts and try to ignite religious conflicts in societies'
The Burj Khalifa’s official page on Instagram said, “BurjKhalifa lights up in solidarity with #SriLanka. Here’s to a world built on tolerance and coexistence…”
Intelligence warnings from abroad alerting to possible attacks by Islamist extremists were ignored ahead of the multiple bombings of churches and upscale hotels on April 21 that killed 253 people and injured nearly 500.
Saudi Arabia, Kuwait, Iraq, Turkey, Pakistan and Afghanistan imposed restrictions on travel and immigration from Iran
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