Pope Francis on Sunday appealed for peace in Gaza during his weekly Angelus prayer, calling for "concrete gestures to build peace" as the deadly six-day offensive escalated. In an address to thousands of pilgrims on St Peter's Square Francis spoke of the "tragic events of the last few days." "I urge all interested parties and all in local and international political office not to spare in prayer and efforts to cease all hostilities," Francis added. Pope Francis's remarks follow a controversial visit earlier this year, whereby the pope called the Palestinian Authority (PA) the " state of Palestine " and then made an unexpected stop at the security barrier between Jerusalem and Bethlehem to pray at a section with " Pope we need to see someone to speak about justice. Bethlehem look like Warsaw ghetto. Free Palestine" spray-painted on it. In June, he held a joint "prayer for peace" in the Vatican with Israeli President Shimon Peres and Palestinian Authority Chairman Mahmoud Abbas. Referring to the June 8 joint prayer , he said: "Some people might think that such a meeting was in vain. But this is not the case because prayer helps us not to be conquered by evil or resign ourselves to violence and hatred." Pope Francis joins a chorus of calls for a cease-fire to be convened and peace talks to be resumed since Israel began defending itself against the rocket fire six days ago.