Leaders of the world’s Muslim countries announced on Wednesday that they recognized East Jerusalem as the capital of Palestine and called on the United States to reverse its decision recognizing the contested city as Israel’s capital, firing a salvo in the bitter dispute over the ancient site claimed by both Israelis and Palestinians.

The decision, made at an Organization of Islamic Cooperation (OIC) summit in Istanbul, followed Turkish President Recep Tayyip Erdogan’s call to the group to acknowledge Jerusalem as the Palestinians’ rightful capital.

Erdogan has reportedly sought to lead the response to US President Donald Trump’s declaration last week that Washington sees Jerusalem as the capital of Israel, a move welcomed by Israeli Prime Minister Benjamin Netanyahu but condemned by Muslim countries around the world. The declaration unleashed violence that killed at least two Palestinians in protests last week.

Erdogan organized the OIC summit in an effort to form coherent opposition to Trump’s move as Arab leaders scrambled to respond. In a final communique obtained by Al-Monitor, the OIC said it was “declaring East Jerusalem as the capital of the State of Palestine and inviting all countries to recognize the State of Palestine and East Jerusalem as its occupied capital.”