Pope Francis calls Russian invasion 'unacceptable armed aggression'

March 13 (UPI) -- Pope Francis on Sunday called the Russian invasion of Ukraine an "unacceptable armed aggression" as he urged for a diplomatic end to the war and the establishment of humanitarian corridors.

In his statements, Pope Francis expressed horror over "the barbarity of the killing of children" and unarmed civilians and urged for an end to the invasion "before it reduces cities to cemeteries," according to Vatican News, a state-run broadcaster owned by the Holy See.

"In the name of God, let the cries of those who suffer be heard and let the bombings and attacks cease! Let there be a real and decisive focus on negotiation, and let the humanitarian corridors be effective and safe," Pope Francis said. "In the name of God, I ask you: stop this massacre!"

Pope Francis also said that Mariupol has "become a city of martyrs" amid the constant shelling by Russian forces that had disrupted most humanitarian corridors established to evacuate and help civilians in the country.

Doctors Without Borders said in a statement Friday that the humanitarian crisis in Mariupol is "extremely dire" as Russian forces continue the shelling of the city.

The humanitarian organization said it cannot enter the city to provide aid and civilians cannot flee, with residents suffering from dehydration, skin infections caused by crowding and respiratory infections.

Cardinal Konrad Krajewski, the Papal Almoner, visited Ukraine last week to meet with religious leaders in the country and provide humanitarian aid from the Vatican.

"[I went to Ukraine] also to thank the people of good will who are offering their homes to refugees, the many volunteers in Ukraine and also the many donors," the cardinal told Vatican News.

"The mayors and prefects of the area came with us, despite the air raid sirens warning them to take cover. We prayed and talked about the near future. There is great hope for the future but the weapons must be stopped and the sun must finally rise over Ukraine as well."

In Italy, a bus carrying 50 passengers from Ukraine driving on the A14 highway went off the road between Forli and Cesena and overturned causing the death of one passenger and injuring others, firefighters said in a statement.

Officials posted a video of two cranes working to flip the overturned bus.