UN observers' spokesperson said Tuesday that a team of observers trying to reach the town of al- Haffeh in northern Syria earlier in the day were confronted with angry crowds that surrounded their vehicles, stopping them from proceeding any further.

"The crowd, who appeared to be residents of the area, then hurled stones and metal rods at the UN vehicles," Sausan Ghosheh said in a statement emailed to Xinhua.

She said the UN observers turned back after the incident in al- Haffeh, adding that as they were leaving the area, three vehicles heading towards Idlib came under fire.

"The source of fire is still unclear," she said, adding that all UN observers are now back at their bases and are secure.

The UN Supervision Mission in Syria (UNSMIS) has been trying to reach al-Haffeh since June 7 but has been impeded by the ongoing violence in the area. UNSMIS calls on the parties to grant the UN observers immediate and unfettered access to conflict zones.

Syria's state media said a group of UN observers patrolled Tuesday the restive mountainous town of al-Haffeh near Syria's coastal Latakia province.

SANA reported Tuesday that the observers entered the town, which has been the scene of intense fighting between government troops and armed groups since a week ago. SANA added that the government troops are pursuing remnants of the armed groups in al- Haffeh.

A pro-government Facebook news page, Ajel network, said the UN team was pelted with stones and sticks by unknown mobs when it was heading from Latakia towards al-Haffeh. The team was attacked at the entrance of the restive town, which prompted the law- enforcement forces to shot in the air to disperse the rowdy crowd, it said.

One of the team's vehicles ran over a crowd of people when it was fleeing the scene, leaving three people injured, two of them were reported killed, it said.

The observers' spokesperson didn't comment on the two casualties.

The UN-Arab League joint envoy to Syria Kofi Annan expressed worries Monday about the escalation of violence in the unrest-torn country, especially after reports about use of mortar shells and tanks in Homs and al-Haffeh, according a statement issued by Annan 's spokesman Ahamd Fawzi.

The UN estimates that over 9,000 people have died in Syria's 15- month-old unrest, while the Syrian authorities said they are fighting foreign-backed armed groups and over 2,000 troops were killed during attacks on government establishments.

 VietNamNet/Xinhuanet