|It has been eight months since the uprising began, prompting a violent crackdown by the government [Reuters]
Forces loyal to Syrian President Bashar al-Assad have fought members of the army that have joined anti-government protesters in the northwestern town of Maarat al-Noman, residents and activists say.
The clash took place at a roadblock near the town, where soldiers backing the protesters have been sheltering, in Idlib province.
"A firefight broke out in the early afternoon at the large barrier which is manned by soldiers and military intelligence personnel. Tanks are also deployed there," a local resident, who gave his name as Raed, told the Reuters news agency by telephone on Tuesday.
Raed said that the roadblock had been attacked in response to a military operation on defectors sheltering in a chicken factory on the outskirts of the town.
The Syrian Observatory for Human Rights, a London-based group, said that seven security agents had been killed in the Maarat al-Noman clashes, after their convoy was attacked by army deserters.
"Armed men, suspected deserters, attacked a security forces convoy at the entrance to Maarat al-Noman town in Idlib province, killing seven agents, including an officer," the group said in a statement on Monday.
It said that the convoy consisted of 40 vehicles, including buses, four-wheel drive cars and other vehicles.
"Ambulances rushed to the scene of the attack which was completely sealed of," it said.
The attack took place at 1:00pm local time (11:00 GMT) and gunfire could be heard in the early afternoon, the group said.
The report could not be independently verified because the Syrian government has restricted reporting in the country.
Maraat al-Noman is located in an agricultural area along Syria's main northern highway, about 100km north of the city of Homs and and 70km from Aleppo.
It was a hotbed of resistance to Assad's father, Hafiz, in the 1980s, when his forces crushed Islamist and leftist challenges to his rule.
Call for protection
Meanwhile, a key Syrian opposition group has called for the international community to take steps to protect civilians in the country from a government crackdown, ahead of an expected visit to Damascus by senior Arab officials.
In-depth coverage of escalating violence across Syria
The delegation will be led by Hamad bin Jassim bin Jaber al-Thani, the Qatari prime minister, and is expected to arrive on Wednesday to discuss the possibility of starting a national dialogue between the opposition and Assad's government.
In a statement, the opposition Syrian National Council said it would not engage in any dialogue with the government while the crackdown continued.
The United Nations says that the Syrian government has killed 3,000 people since the uprising against Assad began in March.
The council called for Arab and international observers to be allowed into Syria, though it did not elaborate on what role they would play.
China on Tuesday announced that it would be sending a special envoy to Damascus, and urged the government to heed the "reasonable" demands of the Syrian people.
"We hope that all sides in Syria can put the interests of the country and people first, discard violence, avoid bloodshed and clashes, and resolve differences via dialogue in a peaceful way," said Jiang Yu, a Chinese foreign ministry spokeswoman.
"We believe that Syria's government should proactively fulfill its promises of reform, and answer the people's reasonable demands," she told a regular news briefing.
Concerns regarding rights abuses in Syria continue to mount, and on Tuesday a report alleged that patients in Syrian state hospitals had been subjected to torture and mistreatment.
The report from Amnesty International, a London-based rights group, also alleged that medics who had helped protesters had been targeted by security forces.
"The Syrian government has turned hospitals into instruments of repression in its efforts to crush opposition," Amnesty said in the report , released late on Monday.
The report documented how wounded patients in at least four government-run hospitals had been subjected to torture and other ill-treatment, both by medical workers and by security personnel.
"It is deeply alarming that the Syrian authorities seem to have given the security forces a free rein in hospitals, and that in many cases hospital staff appear to have taken part in torture and ill treatment of the very people they are supposed to care for," said Cilina Nasser, Amnesty International's Middle East and North Africa researcher.
Meanwhile Radwan Ziadeh, a leading Syrian rights activist and co-founder of the Damascus Centre for Human Rights, told a media conference in New York that the Syrian govenrment had detained more than 30,000 people since the crackdown began.