|New footage has emerged which appears to show Syrian soldiers clashing with armed opposition fighters [Al Jazeera]
Dozens of people have been killed in Syria, including civilians and army defectors, as security forces continue their crackdown on ongoing anti-government protests, activists say.
They said security forces opened fire on activists and ordinary civilians on Thursday as they conducted raids in search of dissidents in areas including the capital Damascus, Deir al-Zour, Idlib, Hama and Homs, which has emerged as the epicentre of the uprising.
An eight-year-old girl was among the victims in Homs, Rami Abdul-Rahman, head of the British-based Syrian Observatory for Human Rights, said.
The Local Co-ordination Committees, an activist coalition, also reported civilians killed in these areas.
There were reports of deadly clashes between army defectors and soldiers near the eastern city of Deir al-Zour and near Maarat al-Numan, a town on the highway linking Damascus and the major city of Aleppo.
"Where basic human rights are trampled and peaceful demands for change met by brutal violence, people are eventually compelled to have recourse to rebellion against tyranny and oppression."
- Navi Pillay, UN human rights chief
This comes as new video emerged on the internet of Syrian soldiers coming under fire from some apparently heavily armed opposition fighters.
The footage, reportedly shot on Sunday, seems to add to claims that suggest opposition groups are arming themselves in the fight against government forces.
Syria has barred most foreign media, making it difficult to verify death tolls as well as accounts from activists and officials.
'Crimes against humanity'
The UN estimates about 3,500 people have been killed since the uprising against President Bashar al-Assad's government began eight months ago, inspired by the revolutions in Egypt and Tunisia.
Watchdog group Human Rights Watch (HRW) on Friday accused Syrian government forces of "crimes against humanity" based on the systematic nature of abuses against civilians.
HRW urged the Arab League to suspend Syria's membership, and also called on the body to ask the UN Security Council to impose an arms embargo and sanctions against responsible individuals, and to refer Syria to the International Criminal Court.
"The systematic nature of abuses against civilians in Homs by Syrian government forces, including torture and unlawful killings, indicate that crimes against humanity have been committed," it said.
Based on the accounts of 110 victims and witnesses, the report said "violations by the Syrian security forces killed at least 587 civilians" in the central city of Homs and its province between mid-April and the end of August.
HRW said protesters were unarmed in most clashes, but that defectors from the security forces intervened when the demonstrators came under fire from regime troops and militiamen.
"Violence by protesters or defectors deserves further investigation," said the report, adding however that "these incidents by no means justify the disproportionate and systematic use of lethal force against demonstrators".
Navi Pillay, the UN human rights chief, told the Security Council on Wednesday that an increasing number of Syrian soldiers are defecting, raising the risk of a Libya-style civil war.
"Where basic human rights are trampled and peaceful demands for change met by brutal violence, people are eventually compelled to have recourse to rebellion against tyranny and oppression," she said.
It is difficult to gauge how many people have defected from the army and what kind of threat they pose to the government. Although the crackdown has led to broad international isolation of Assad, he appears to have a firm grip on power, retaining the loyalty of most of the armed forces.
Assad, and his father who ruled Syria before him, stacked key security and military posts with members of their minority Alawite sect over the past 40 years, ensuring loyalty by melding the fate of the army and the government.
As a result, the army leadership will likely protect the government at all costs, for fear it will be persecuted if the country's Sunni majority gains the upper hand. Most of the army defectors so far appear to be lower-level Sunni conscripts.
Syria's two main opposition groups, the National Co-ordination Committee (NCC) and the Syria National Council, again met Nabil Elaraby, the head of the Arab League, on Thursday, despite internal quarrels over whether to request foreign military assistance and accept dialogue with Assad.
After the meeting concluded, Abdul-Aziz al-Khair, spokesman for the NCC, called on the Arab League to send observers to Syria to see for themselves the violence he said was being meted out by the government.
About 100 protesters in Cairo threw eggs and tomatoes at a four-man delegation from the NCC on Wednesday as the group tried to enter the Arab League's headquarters for a meeting.
In-depth coverage of escalating violence across Syria
Critics say the NCC, which includes veteran activists and former political prisoners, is far too lenient and willing to engage in dialogue.
The other group taking part in the talks, the Syrian National Council, rejects all forms of contact with the Assad government under the current crackdown.
The divisions have thus far prevented the opposition from gaining the traction it needs to present a credible alternative.
Syria agreed to a peace plan brokered by the Arab League last week, but officials say Damascus has since failed to abide by its commitments to pull tanks and other armour out of cities and stop the bloodshed.
It was not clear what action the league would take if the bloodshed continues, although it could isolate Syria with the Arab world by suspending or freezing its membership.