Syrian forces have bombarded districts of the city of Homs in their drive to crush a revolt against President Bashar al-Assad, as Arab foreign ministers meet to discuss setting up a joint observer mission with the United Nations.
Ministers from the Arab League, which suspended Syria's membership in response to the crackdown, met in Cairo on Sunday to discuss forming a joint UN-Arab League monitoring team in place of a league observer mission that was suspended last month.
Sources told Al Jazeera that the league is going to form a new mission of about 3,000 observers that has an international character, under the supervision of the Arab League.
Al Jazeera's Rawya Rageh, reporting from Cairo, said that even after Russia and China vetoed a harsh UN resolution against Syria, the Arab League ministers are still banking on support.
"Another discussion they are having is to perhaps expand the observer mission to include other countries, or change the mandate to be one of peace keepers," she said.
League Chairman Nabil el-Arabi said on Sunday that message received from Russian Foreign Minister Sergei Lavrov indicted Moscow would support the expansion of the monitoring mission.
Arabi also accepted the resignation of Sudanese General Mohammed al-Dabi, who led the first monitoring mission, and proposed appointing former Jordanian Foreign Minister Abdul Ilah al-Khatib as a special envoy, Egypt's state news agency reported.
The new mission is expected to include observers from Arab and Muslim states, and other foreign countries will provide more sophisticated equipment to aid the mission.
Tunisia will host a "Friends of Syria" meeting on February 24 to attempt to build an international consensus on how to end the violence. Tunisia's foreign minister said the meeting will include Arab, regional and international states, and Qatari Prime Minister Sheikh Hamad bin Jassim Al Thani, who is also the country's foreign minister, said he backed the proposal.
An official source at the league said another proposal called for the appointment of a UN-Arab League envoy to deal with Syria, adding that some states may also propose the league formally recognise the opposition Syrian National Council (SNC).
"Its a very difficult process to recognise the SNC - the Arab League made it clear to the opposition that the body as a whole cannot do it, but rather the individual countries will need to do that on their own," Rageh said.
"The GCC countries were the first to recognise the Libya last year, and also the first to take drastic steps with regards to Syria."
Meanwhile, the siege on the city of Homs has continued, with rights groups saying at least four people were killed during Saturday's violence, and that three bodies of people who had been killed earlier were also recovered.
Hussein Shobokshi, a columnist for the Asharq Alawsat newspaper in Saudi Arabia, told Al Jazeera that a lot of pressure was being built up against the Syrian government.
"Its the responsibility of the international community, not just the Arab League to stop this violence," Shobokshi said.
"The situation is catastrophic and there needs to be international stand, at least from a humanitarian point of view."
Opposition neighbourhoods in Homs were hit by tank and rocket bombardments in the government's continuing crackdown on protesters there, with the city's Bab Amr area coming under concerted fire.
Security forces have also made house-to-house raids over the last two days in Homs, which has been under siege for the last week, anti-government activists have said.
They say at least 300 people have been killed there since the government's latest assault began on February 4.
In Hama, the Syrian Revolutionary General Commission (SRGC), a rights group that has organised protests against President Bashar al-Assad's rule, says that the army is continuing to maintain a heavy presence.
The group said troops raided the city's al-Sharia neighbourhood and that heavy gunfire and mass arrests were reported from there and at least three other districts.
Reports of violence between security forces and anti-Assad forces were also reported from Zabadani and Douma, which is just outside the capital Damascus.
The SRGC said that at least 46 people were killed in Saturday's violence: 20 in Homs, 11 in Deraa, 11 outside Damascus, three in Idlib and one in Hama.
Elsewhere, the Syrian Observatory for Human Rights (SOHR), an UK-based rights group, reported that 10 soldiers were killed in an ambush by army defectors on Friday in the Idlib area, near the Turkish border.
The defectors hit a patrol between two villages with hand grenades and roadside bombs, the SOHR said.
Army defectors also fought government troops for hours overnight in the al-Qaboun neighbourhood of Damascus.
Also in Damascus, state media reported that anti-government forces had killed a senior Syrian military doctor outside his home.
The SANA news agency reported that "an armed terrorist group" had killed Brigadier-General Issa al-Khouli, who it described as a doctor and hospital director, in the Rukneddine district of the Syrian capital on Saturday.
The Revolution Leadership Council, an anti-Assad group in Damascus, alleged that the government had carried out the killing itself.
Meanwhile, the armed opposition has denied claims from the government that it carried out bomb attacks in the northern city of Aleppo that left dozens of people dead on Friday.
Speaking to Al Jazeera, Arif al-Hummoud, a commander of the Free Syrian Army, a name used by various armed groups, said that opposition fighters had carried out an attack on Friday morning but were not responsible for the blasts.
"A group from the Free Syrian Army attacked a branch of the military security and a security unit in Aleppo with only [rocket-propelled grenades] and light weapons," he said.
In-depth coverage of escalating violence across Syria
Syrian state television quoted the health ministry as saying that 28 people were killed and more than 200 others wounded, including soldiers and civilians, in the attack and said it was carried out by "armed terrorist groups".
Abdul Rahman Abu Hothyfa, a spokesman for the opposition Syrian Revolution Co-ordinators Union, told Al Jazeera that it was "absolutely the regime" that carried out the attack.
Security forces opened fire on the protesters in several Aleppo neighbourhoods after Friday prayers, killing at least six people, according to the Local Co-ordination Committees, an umbrella organisation of anti-Assad activists.
The activist network said 12 people were killed in the province and at least 23 more in other parts of the country on Friday.
In addition to the victims of the attacks in Aleppo, the observatory said another 44 people were killed across Syria on Friday, including 28 civilians, nine soldiers and seven deserters.
Security forces deployed heavily outside mosques nationwide, firing on worshippers in some areas to prevent protests denouncing Russia's steadfast support for the Assad regime, activists said.
An activist in Homs giving her name as Salam al-Homsi said it was getting more difficult to save those injured.
"We can't even get them out of the rubble because the snipers won't let people help the wounded," she said. "There are no medical supplies and people are dying in the field hospitals. It's getting worse and worse."