The Organization of Islamic Cooperation (OIC) has suspended Syria from membership, a Saudi Arabian official announced.
“There is a strong concern over the massacres and the inhumane acts that are being committed against the Syrian people,” Nizar bin Obaid Madani, state minister for foreign affairs, was quoted by CNN as having said.
“Therefore the leaders agreed on the importance of preserving the unity of Syria, the immediate end of all acts of violence and the suspension of Syrian membership within OIC,” the minister said after a two-day summit of OIC heads of state.
On Monday, foreign ministers of the OIC agreed to suspend Syria from the international body, but the decision was made formal during a vote taken by OIC leaders.
Iran opposed the move by the group, which represents 1.5 billion Muslims and comprises 56 member states and the Palestinian Authority.
The development came as would-be rescuers searched for survivors amid the rubble left after Syrian government forces shelled a town in Aleppo province near the border with Turkey.
Earlier estimates said that 31 people had been killed in the shelling of the town of Azaz. A spokesman for the rebel Syrian National Council told CNN that 40 people had been killed.
“We have no special equipment to search or lift the wreckage,” said the spokesman, Abu Omar. “People are doing it using their bare hands and rudimentary tools.”
Another 40 people in Azaz were missing after the shelling, which targeted a popular food market, Omar said.
Among the dead were four Lebanese hostages who had been taken by an armed group called "the revolutionaries of Aleppo" that is not affiliated with the Free Syrian Army, he added.
Omar described the victims as civilians, including women and children, and said the town was without electricity.
Meanwhile, the reports of Lebanese being killed or abducted in Syria heightened tensions in the neighboring country.
CNN cited the Lebanese official National News Agency (NNA) as having reported that the brother of a man kidnapped in Syria said that his family had, in turn, kidnapped 26 Syrian nationals in Lebanon and was threatening to kidnap Qatari, Saudi and Turkish nationals.
NNA said it was the Free Syrian Army that had detained in Damascus Hassan Salim Meqdad, the brother of Hatem Meqdad, for allegedly belonging to Hizbullah.
Four of the abducted Syrians were freed after they proved to have no link to the FSA, said the report.
Kuwait's Foreign Ministry was urging the evacuation of all Kuwaiti nationals from Lebanon in response to the "deteriorating security situation," a senior ministry official told the Kuwaiti state news agency.
The Saudi Press Agency, meanwhile, reported that the Saudi Embassy in Lebanon was urging all Saudi citizens to leave the country, "given the latest events in Lebanon and the declared threats to kidnap Saudis and others in Lebanon."
Earlier on Wednesday, Syrian rebels claimed they destroyed Assad’s military headquarters with a serious of simultaneous bomb blasts.
The Syrian government claimed that no one was killed and that the explosion was close to a nearby hotel, but it is difficult to confirm any news from Syria because of the official ban on foreign journalists.