After reciting the Angelus prayer with thousands of visitors in St. Peter's Square July 24, the Pope conveyed his sadness at "the tragic events in Munich, Germany, and in Kabul, Afghanistan, where many innocent people have lost their lives."

"To the extent that the difficulties seem more insurmountable and the prospects of security and peace seem more unclear, our prayer should be more insistent," he said.

Tragedy struck Munich July 22 when 18-year-old gunman David Ali Sonboly shot and killed nine people and wounded 35 others before killing himself during a shooting spree at a shopping centre. Investigators said that they could find no clear motive and no known links to terror organizations.

The following day, two suicide bombers detonated their explosives during a peaceful protest by a group of Shiite Muslims in Kabul, Afghanistan. A third bomber was killed by security forces before he could detonate his bomb.

The Islamic State group claimed responsibility for the attack that claimed the lives of more than 80 people and left more than 240 wounded.

Pope Francis assured his "closeness to the families of the victims and the wounded" in both attacks.

"I invite you to join with me in prayer so that the Lord inspires in everyone resolutions of goodness and fraternity," the Pope said after his Angelus address.

The same day, a suicide bomber killed 21 people and wounded at least 35 others in an attack in a neighbourhood of Baghdad. The Islamic State group also claimed responsibility for that attack.