COLOMBO - Former Sri Lankan president Mahinda Rajapaksa has called the multiple attacks on churches and hotels in Sri Lanka "absolutely barbaric", and said that the nation will stand united as one against "acts of terrorism".

"It is absolutely barbaric to see such violent attacks on such a holy day. Whoever is behind these attacks must be dealt with immediately. My thoughts and prayers are with the families that lost loved ones and all of Sri Lanka," Mr Rajapaksa said in a tweet on Sunday (April 21).

"We will not tolerate such violence, such acts of terrorism, of cowardice within our borders once again. We will stand together and rise up against it as one voice. We will stand united as a nation. #UnitedWeStand."

More than 100 people were killed and over 400 injured after three Sri Lankan churches and three hotels were hit by a string of explosions on Easter Sunday.

Other world leaders and the Catholic Church have also strongly condemned the attacks and pledged their support for Sri Lanka.

INDIA

In a tweet on Sunday, Indian Prime Minister Narendra Modi said the country "stands in solidarity with the people of Sri Lanka".

"Strongly condemn the horrific blasts in Sri Lanka. There is no place for such barbarism in our region. India stands in solidarity with the people of Sri Lanka. My thoughts are with the bereaved families and prayers with the injured," Mr Modi said.

India, Sri Lanka's northern neighbour, was keeping a close watch on the situation on the island country. External affairs minister Sushma Swaraj said she was in constant touch with the Indian envoy in Colombo and that the mission will provide all possible assistance to Indians in distress.

MALAYSIA

Malaysian prime minister-in-waiting Anwar Ibrahim called the attacks "a horrible and senseless tragedy".

"A horrible & senseless tragedy on a holy day for our Christian friends. Our thoughts & prayers are with the victims & their mourning families, just as our support is with the government in bringing the perpetrators to justice," Datuk Seri Anwar said in a tweet on Sunday.

Mr Anwar's wife, Datuk Seri Wan Azizah Wan Ismail, also took to Twitter to express her condemnation of the attacks.

"I strongly condemn the act of terrorism that killed more than 130 people in Sri Lanka today. Easter is a joyous occasion for Christians and to commit such an act on such a day or any day is truly condemnable. Our prayers are with with Sri Lankans during this difficult period," the deputy prime minister said in her tweet.

CATHOLIC CHURCH

The Catholic Church in Israel voiced support for Sri Lanka's Christians and condemned the attacks, Agence France-Presse reported on Sunday.

A statement issued in Jerusalem said the blasts were particularly sad as they "came while Christians celebrate Easter".

"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," the statement said. "We also express our solidarity with Sri Lanka and all its inhabitants in their various religious and ethnic backgrounds."

The nature of the blasts was not immediately clear and there were no immediate claims of responsibility.

AUSTRALIA

Australian Prime Minister Scott Morrison said Australia was thinking of those killed in a "horrific terrorist attack".

"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," he said in a statement.

"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

A month after dozens of Muslims were killed in a shooting at two mosques in Christchurch, New Zealand Prime Minister Jacinda Ardern described the attack in Sri Lanka as "devastating", Agence France-Presse reported.

"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," she said.

"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."

BRITAIN

British Prime Minister Theresa May condemned the deadly attacks on Christians 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. We must stand together to make sure that no one should ever have to practise their faith in fear," she said on Twitter.

GERMANY

The German government expressed shock over the series of bombings in Sri Lanka. "We're horrified by the news that Christians in Sri Lanka were attacked and killed during Easter services," wrote Chancellor Angela Merkel's spokesman on Twitter.

"We mourn them and pray for the injured and their family members. Terrorism, religious hatred and intolerance cannot be allowed to win," added the spokesman.

The German Foreign Office's crisis reaction centre wrote that the situation in Sri Lanka was unclear and that it was trying to determine whether German nationals were affected by the attack, DPA news agency reported.

THE NETHERLANDS

"Terrible reports from Sri Lanka about bloody attacks on hotels and churches on this Easter Sunday," Dutch Prime Minister Mark Rutte tweeted after the attacks first emerged. "Thoughts are with the victims and their relatives."

EUROPEAN UNION

European Commission chief Jean-Claude Juncker expressed his "horror and sadness" after the attacks.

"It was with horror and sadness that I heard of the bombings in Sri Lanka costing the lives of so many people," Mr Juncker said on Twitter, adding that the European Union stood ready to help.

"I offer my heartfelt condolences to the families of the victims who had gathered to worship peacefully or come to visit this beautiful country," he said.

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.

AFGHANISTAN

In Kabul, Afghan President Ashraf Ghani "strongly" condemned the series of coordinated explosions. Mr Ghani sent his "deepest condolences to the victims and their families who lost their dear ones on this sacred (Easter)", DPA reported.

Mr Ghani added that "targeting worshippers is appalling", saying that Afghanistan stands "in solidarity" with Sri Lanka "on this dark day".

JORDAN

Jordan's Foreign Minister Ayman Safadi said on his official Twitter account: "Our thoughts and prayers are with the victims of the ugly terrorist attacks against innocent worshippers and civilians in Sri Lanka."

"Our deepest condolences... We strongly condemn these horrific crimes as we stand together in the fight against terrorism and its ideology of hate," Mr Safadi said, according to Xinhua.