Syrian tanks in Deir al-Zor Saudi Arabia, Kuwait and Bahrain recalled their Damascus envoys as Sunni Islam's top body on Monday urged an end to the crisis in Syria, increasing the regional isolation of President Bashar al-Assad.
Hours after the Saudi envoy's recall, rights activists said security forces shot dead a mother and her two children in the eastern city of Deir Ezzor, where 42 people were reported killed in an army assault on Sunday.
The recalls by Riyadh, the Arab world's Sunni Muslim heavyweight, and fellow Gulf Cooperation Council (GCC) members Kuwait and Bahrain marked a major escalation of pressure on Assad.
His regime's repression of a pro-democracy uprising has left at least 2,059 people dead, including almost 400 members of the security forces, according to the Syrian Observatory for Human Rights.
"Saudi Arabia announces the recall of its ambassador for consultations," King Abdullah said in a statement after Syrian security forces killed more than 50 people on Sunday.
He urged Damascus to "stop the killing machine and the bloodshed... before it is too late."
"The kingdom does not accept the situation in Syria, because the developments cannot be justified," King Abdullah said, urging "comprehensive and quick reforms."
"The future of Syria lies between two options: either Syria chooses willingly to resort to reason, or faces being swept into deep chaos, God forbid," he said.
The Saudi decision to recall its ambassador from Damascus was followed by Kuwait and Bahrain.
"No one can accept the bloodshed in Syria... The military option must be halted," Kuwait's Foreign Minister Sheikh Mohammad al-Sabah told reporters.
"There will be a meeting for the GCC foreign ministers soon and a joint GCC move to discuss the issues related to Syria."
Bahrain's Foreign Minister, Sheikh Khaled bin Ahmad al-Khalifa, also said on Monday his country was recalling its ambassador for "consultations."
In Cairo, Sheikh Ahmed al-Tayeb, the grand imam of Al-Azhar, the leading authority in Sunni Islam, called for an end to the "tragedy" in Syria, saying "the situation has gone too far," in a statement.
Al-Azhar "asks Syrian leaders to work immediately to end the bloodshed and to respond favourably to the legitimate demands of the Syrian masses," he said.
Security forces on Monday shot dead a mother and her two children fleeing the military assault on Deir Ezzor, the Britain-based Syrian Observatory said, quoting local residents.
"The woman and her two children were trying to flee the Huweika district for somewhere safer when they were targeted by a security patrol," residents said, adding that the father of the family was wounded.
An elderly woman was also killed in the city's Al-Jura district, according to the rights group.
Activists said security forces backed by tanks killed 42 civilians in Deir Ezzor on Sunday and at least 10 more in the central town of Hula, as Assad defended the actions of his security forces.
"To deal with outlaws who cut off roads, seal towns and terrorise residents is a duty of the state which must defend security and protect the lives of civilians," he said.
State news agency SANA also quoted an official military source as denying charges that tanks were shelling Deir Ezzor.
The Arab League on Sunday made its first official statement on the unrest, urging Damascus to "immediately" stop the violence with Secretary General Nabil al-Arabi calling for an "impartial probe" into the bloodshed.
US and European leaders already pledged to consider new steps to punish Syria after security forces killed more than 30 people on the first Friday of Ramadan, the holy Muslim month of fasting.
EU nations are eyeing new sanctions against individuals and businesses linked to the clampdown, EU diplomats asking not to be identified said on Monday.
Germany warned that Assad will forfeit legitimacy if his regime continues the deadly crackdown.
"If President Assad maintains his refusal to engage in dialogue with the Syrian people and continues to resort to violence, the German government will consider he has forfeited his legitimacy in further overseeing the fate of his country," deputy government spokesman Christoph Steegmans told reporters.
The Assad regime has pledged reform and blamed "armed terrorist gangs" for the almost five-month-long unrest.
Witnesses and activists on Monday reported tanks and troops entering Maaret al-Numan in Idlib province bordering Turkey and carrying out "a large number of arrests."
On Sunday night, demonstrations were reported in the central city of Homs, with the Syrian Observatory saying security forces wounded at least one protester.