On behalf of Pope Francis, the Vatican’s Secretariat of State has sent a letter to the archbishop of Tunisia, assuring him of the Pope’s prayers after yesterday’s deadly terrorist attack killed at least 23 people.

In the March 19 telegram, Pope Francis called the attack “(an act) against peace and the sacredness of human life.” He said that he unites with prayer “to the suffering of the families (of the victims) and to all those affected by this tragedy, as well as to the entire Tunisian people.”

Francis closed his letter by asking the Lord “to welcome the deceased in peace and comfort those who are seriously injured.”

Signed by Vatican Secretary of State Cardinal Pietro Parolin, the telegram was addressed to Mons. Ilario Antoniazzi, archbishop of Tunisia, following yesterday’s attack on the country’s National Bardo Museum, which is a popular tourist destination.

Reports indicate that roughly 200 tourists were visiting the museum when three gunmen dressed in Tunisian military uniforms opened fire on several buses before storming inside the museum itself.

BBC News reports that in a new audio message released by the Islamic State, the militants claimed responsibility for the attack, saying it was carried out by “two knights of the caliphate.”

Tunisian police have reportedly arrested nine people suspected of having a hand in the attack, which left 23 people dead and 40 wounded. Two gunmen were killed at the scene, according to the BBC.

Among the tourists killed are foreigners hailing from Japan, Italy, Colombia, Spain, the UK, Australia, France and Poland. Three Tunisians are also reported to have been killed, including a police officer.

At the time of the attack, officials in the neighboring parliament building had been discussing anti-terrorism legislation.

Tunisia recently completed its first free presidential elections with a peaceful transition of political power after leading a democratic reform movement in 2010 which resulted in the outing of the country’s longstanding ruler.

The country’s revolution launched a wave of demonstrations, protests and riots across the Arab world – the start of what came to be known as the Arab Spring.

While the Tunisian government has sought to put an end to occasional attacks by Islamist extremists, the country has regardless become one of the largest providers of fighters joining ISIS forces in Syria and Iraq, The New York Times reports.

Yesterday’s assault marked the deadliest terrorist attack since a truck filled with propane exploded outside of a synagogue on the island of Djerba in 2002, killing 21 people, including European tourists.