STANBUL (AP) — U.N. Secretary-General Ban Ki-moon has called on Syria to stop its attacks, saying U.N. observers monitoring the ceasefire were not there to watch the killings of innocent people.

Ban was speaking Thursday at a summit of the Alliance of Civilizations, a forum promoting understanding between the Western and Islamic worlds, days after more than 100 people were massacred in Syria's central Houla region.

Turkish Prime Minister Recep Tayyip Erdogan, meanwhile, called on the world to listen to their conscience and see the desperation of families whose children are massacred in Syria.

Recep Tayyip Erdogan says these are "our children who are massacred in Hama, Homs and Houla, as much they are the children of desperate Syrian families."

Erdogan says the world should not remain silent in the face of "oppression."