President Bashar al-Assad's opponents have appealed for foreign help to stop the killing of civilians by regime forces as protesters prepare to take to the streets once again, six months since anti-government demonstrations began.
In a first direct call by the opposition for foreign intervention, Syria's underground opposition said a rise in the number of protesters killed during the revolt had won over many reluctant Syrians to the need for outside help.
The Syrian Revolution General Commission umbrella bloc of activists appealed to the international community on Thursday to send in human rights monitors to help deter military attacks on civilians in the increasingly bloody crackdown.
"Calling for outside intervention is a sensitive issue that could be used by the regime to label its opponents as traitors. We are calling for international observers as a first step," spokesman Ahmad al-Khatib told the Reuters news agency.
"If the regime refuses it will open the door on itself for other action, such as no-tank or no-fly zones," he said, adding that Assad's forces had killed 3,000 civilians, thousands had been arrested and thousands more were counted as missing.
Despite the crackdown, protesters across Syria have continued to take to the streets of many towns and cities after Friday prayers in a weekly display of defiance.
The announcement came as Syrian forces arrested dozens of people in house-to-house raids in the city of Homs following military operations that killed at least 28 civilians on Wednesday. Activists and residents also reported more defections among the rank-and-file army.
In the northwestern province of Idlib near the border with Turkey, at least three army defectors were killed by the military as it raided the Jabal al-Zawiya area in pursuit of deserters, local activists said.
In-depth coverage of escalating violence across Syria
The Syrian military launched offensives against the cities of Latakia, Aleppo and Deir al-Zor last month, with Assad repeatedly saying he was fighting a foreign conspiracy to divide Syria and the authorities blaming "armed terrorist groups" for the killings, including 500 members of the army and police.
The argument did not go down well with the West, nor with Turkey, which had once strongly backed Assad.
"Mr. Assad, how can you say you are killing terrorists when you were actually shelling Latakia from the sea and hitting civilian targets?" Recep Tayyip Erdogan, the Turkish prime minister, told Al Jazeera in an interview broadcast on Thursday.
Iran, considered one of Damascus' closest allies, has also placed pressure on Assad's regime to end the crackdown.
Assad should back away from violence and enter talks with the opposition, Iranian President Mahmoud Ahmadinejad said on Wednesday in an interview in Tehran with Portuguese broadcaster Radiotelevisao Portuguesa.
"A military solution is never the right solution," Ahmadinejad said.
"We believe that freedom and justice and respect for others are the rights of all nations. All governments have to recognise these rights," he said. "Problems have to be dealt with through dialogue."