ROME – As Europe reels from a new wave of terrorist attacks, leading bishops across the continent and around the world are drawing on Pope Francis’s new encyclical letter Fratelli Tutti to appeal for peace, brotherhood and mutual respect.

Some bishops, however, are also echoing Pope Francis in another sense, objecting to the use of satirical cartoons to mock religious figures, as the pontiff himself did in 2015 shortly after the Charlie Hebdo controversy erupted in France.

“Whatever the background to the attack today, it must be clear that there is no justification for blind violence,” Vienna Archbishop Cardinal Christoph Schönborn said following a Nov. 2 attack in the city left four people dead.

“During these dramatic hours, I pray with many others who follow the tragic events in the heart of our city through the media for the victims, the emergency services, and that there will be no further bloodshed,” he said.

In less than a month, there have been at least five separate instances of Islamic terrorism in a Europe already struggling to contain the coronavirus pandemic as new lockdowns are imposed.

On the night of Nov. 2, as Austria was preparing for new national restrictions meant to contain increasing coronavirus infections – meaning bars and cafes were filled with people enjoying a final night out before a midnight curfew began – a string of six different attacks were carried out at the same time in Vienna, leaving four people dead, including one of the attackers.

Things began near the city’s main synagogue in a pedestrian alley called Seitenstettengasse and continued for nine minutes. Austrian authorities declared three days of national mourning, with flags flying at half-mast. Children will observe a minute of silence at school Wednesday in honor of the victims.

Last month, French history teacher Samuel Paty was beheaded outside the school he taught at in a suburb of Paris by a Chechen teen who took issue with Paty’s use of satirical cartoons of the Prophet Muhammad, the founder of Islam, as an illustration of free speech.

On Oct. 29, as the French government prepared to launch new measures cracking down on militant Islam, the Notre Dame Basilica in Nice, France became the scene of an attack after a man entered the basilica wielding a foot-long blade. He was shot by police at the scene and was rushed to the hospital in critical condition, but not before killing three people.

The same day, in a separate incident in Avignon, police shot dead a man brandishing a handgun and shouting “Allahu akbar,” an Arabic phrase meaning “God is great” often invoked by radical Islamist terrorists.

Days after the Nice attack, on Oct. 31, Father Nikolas Kakavelakis, a Greek Orthodox priest, was shot twice by an unknown assailant as he closed up his church in Lyon. He has since had surgery and is said to be in stable condition.

French authorities have said they believe the recent spate of killings are all acts of Islamist terrorism, which came amid mounting anger at President Emmanuel Macron’s defense of satirical cartoons of Muhammad.

The attacks all come as the anniversary of the Jan. 7, 2015, attack on French satirical newspaper Charlie Hebdo draws near. In that attack, two Muslim brothers stormed the paper’s headquarters in Paris and killed 12 people after the magazine had published cartoons of the Prophet Muhammad. This month also marks the anniversary of a massive November 2015 terrorist attack in Paris that left 130 people dead.

In a statement following the Nice attack, the French Council of Muslim Worship condemned the incident and asked Muslims to suspend their Oct. 29 celebrations of the birth of Muhammad as an act of solidarity with the victims and their families.

Several bishops, including Pope Francis, have condemned the violence and have urged societal unity and mutual respect.

Following the Nice attack, Pope Francis condemned acts of terror “in the most energetic manner” and asked for unity, assuring of his closeness to the victims and their families.

Responding to the Vienna attacks, the pope expressed his “deep participation” in the suffering of the victims and their families, praying that “violence and hatred cease, and peaceful coexistence is promoted in society.”

In his own statement, Schönborn said he was “deeply affected” by the shootings, saying the fact that the Vienna attacks began in front of the city’s synagogue reminded him of the 1981 assassination attempt at the temple that left two people dead.

Several other Austrian bishops have spoken out in condemnation of the attack, as well as representatives from other Christian denominations.

Bishop Wilhelm Krautwaschl of Graz in a tweet sent Monday called the attacks “terrible,” and voiced thanks to all those working to provide emergency services.

Elsewhere, Bishop Alois Schwarz of St. Pölten posted a picture of a candle to Facebook, saying that “Even if the extent of the alleged attack cannot yet be fully predicted, my thoughts and prayers go to the victims and their families.”

Evangelical bishop Michael Chalupka also took to Twitter to express his condemnation, saying, “When words fail, all I have left is silent prayer for the victims and their relatives and helpers. Vienna holds together for life in this city. Terror will not split the cohesion!”

Similarly, the Evangelical Lutheran superintendent of Vienna, Matthias Geist, said he was “deeply shaken” by the shooting, calling it an “unbelievable attack on peaceful coexistence among the people in Vienna.”

“We remain in solidarity with all forces that promote and maintain the dignity of all people and the integrity of life. We will continue to contribute to maintaining the democratic, constitutional and trusting events in our big city and to consolidating them across all differences of opinion,” he said.

Amid the condemnations of violence and the mourning of victims, some bishops, including Bishop Gervas Rozario of Rajshahi, Bangladesh, have also criticized the use of satirical cartoons of the Prophet Muhammad, saying they shouldn’t be tolerated.

“We acknowledge people have the right to freedom of speech, but it should not be devoid of values and ethics,” Rozario said in a Nov. 2 Facebook post, adding, “There are so many topics for caricatures, but we as Christians cannot support what French satirical magazine Charlie Hebdo has done.”

Vice-president of the Catholic Bishops’ Conference of Bangladesh (CBCB) and chairman of the CBCB’s Commission for Justice and Peace, Rozario said Charlie Hebdo “has committed an unforgivable injustice by publishing caricatures of Prophet Muhammad, the founder of Islam.”

He also voiced frustration that Macron and several French citizens have supported the cartoons, saying, “We should not attack the religious faith of anyone.”

“Pope Francis has been calling for a world based on humanity and fraternity, and we condemn such deplorable acts,” he said. “We also strongly condemn all kinds of violence. Let us learn to respect each other’s religion.”

In 2015, Francis likewise condemned violence in the name of religion, but also suggested free speech should have limits when it comes to matters of faith.

“You cannot provoke,” he said during a flight en route from Sri Lanka to the Philippines in response to a question about the Charlie Hebdo attacks. “You cannot insult the faith of others.”

Follow Elise Ann Allen on Twitter: @eliseannallen