Editor's Note: This story was updated with more quotes and pertinent numbers and facts throughout the day on March 22 and March 23.

VATICAN CITY — On Tuesday, Pope Francis offered prayers for the victims of attacks at an airport and metro station in Belgium, condemning the acts as “blind violence” and praying for peace.

“Upon learning of the attacks in Brussels, which have affected many people, His Holiness Pope Francis entrusted to the mercy of God the people who have lost their lives and joins those close to them in prayer for the death of their relatives,” said Cardinal Pietro Parolin on March 22.

The Vatican’s Secretary of State signed the letter, which was addressed to Archbishop Jozef De Kesel of Mechelen-Brussels on behalf of the Pope.

He said that Francis expresses “deep sympathy for the wounded, for their families and for all those contributing to relief efforts” and is praying that the Lord will bring them comfort and consolation.

Pope Francis, he said, “again condemns the blind violence which has caused so much suffering, and he implores God for the gift of peace, invoking upon the grieving families and on all Belgians the benefit of divine blessings.”

The Pope’s prayers come after at least 31 people were killed and more than 270 injured in March 22 attacks at Brussels Zaventem international airport and a city metro station near buildings belonging to the European Union.

Two blasts hit the airport around 8am local time, tearing through the departure section. The BBC reports that a Belgian prosecutor said the blasts were likely caused by “a suicide bomber.”

According to reports, shots and shouts in Arabic could be heard before the blasts, and an undetonated suicide belt was found after the attacks.

An hour later, in the middle of rush hour, another explosion struck the Maelbeek metro station in Brussels.

The attacks have prompted Belgium to raise its terrorism threat to the highest level and come just four days after Salah Abdeslam, primary fugitive in the Paris attacks, was arrested in Brussels.

ISIS claimed responsibility for the attacks.

In a March 22 statement, the Belgian bishops said they were “appalled” to learn of the attacks and said they “share the anguish of thousands of travelers and their families, aviation professionals and the first responders who are once again called to service.” They offered prayers for all those affected.

“Good Friday has come three days early with these totally absurd actions,” Auxiliary Bishop Jean Kockerols of Mechelen-Brussels said March 22. “I weep with those who weep, wherever they are. The first reaction, completely normal, is to condemn these totally absurd actions.”

“The reaction of Christians ought to be first of all one of compassion with those affected, with those who are grieving,” he continued. “I am thinking of the victims and their families; we are together in prayer, in friendship.”

Bishop Kockerols later joined Archbishop De Kesel in a statement announcing the cancellation of the chrism Mass scheduled for that day at the Brussels cathedral. The two bishops said “we are invited to stay with Mary at the foot of every cross today. By our prayer and friendship, we must surround the victims and their loved ones, their families.”

In the United States, Archbishop Charles Chaput of Philadelphia was among the Catholic leaders who responded to the attacks.

“We join with the Church in Belgium and the entire nation in this moment of intense pain,” he said. “Each life lost was a precious gift from God that has been torn from all those whom it touched.”

The archbishop encouraged prayers for the victims. Noting the passion, death and resurrection of Jesus Christ, he said: “Let us remember that God is the source of love and life and ask him to bring peace to our troubled world.”

The president of the U.S. Conference of Catholic Bishops, Archbishop Joseph Kurtz of Louisville, Ky., also expressed prayers and support: “Approaching Good Friday, seeing the news from your brave and beautiful city deepens our own meditation on the cross. Please be assured of my prayers and unwavering fraternal support. The Church throughout the United States feels this senseless act of violence as a tragedy in our own family. Of course, the terror of the Crucifixion is overcome by the hope of the Resurrection. Through unity, courage and comforting of the victims, the people of Belgium remind me of the apostles comforted by the risen Lord. In the face of unspeakable violence, they refused to allow fear to be their final witness. ... Today, I thank God for the powerful witness of your people in the face of terror.”

European Unions leaders also spoke out.

“These attacks have hit Brussels today, Paris yesterday; but it is Europe as a whole that has been targeted. The European Union and its institutions stand united in the face of terrorism,” said Jean-Claude Juncker, president of the European Commission.

President Donald Tusk of the European Council voiced his “sincerest sympathies” for the victims of the attack. He said the European Union will work “to help Brussels, Belgium and Europe as a whole counter the terror threat which we are all facing.”

“I am horrified by the despicable and cowardly attacks which took place in Brussels today,” said European Parliament President Martin Schulz. “They are born from barbarism and hatred, which do justice to nothing and no one.”