The UN observer force yesterday accused both sides in the Syrian conflict of hampering its peace mission and admitted its limitations in the face of escalating violence.

“Violence, over the past 10 days, has been intensifying, again willingly by both the parties, with losses on both sides and significant risks to our observers,” the force’s chief Major General Robert Mood told a news conference in Damascus.

A UN convoy trying to reach Al-Haffe, a town in northwest Syria under siege by regime troops, came under fire on Tuesday and was forced to turn back by a stone-throwing crowd of pro-regime residents of a nearby village.

The observer team was finally able to visit two days later, finding it all but deserted with a strong stench of dead bodies and most state buildings gutted by fire.

Major General Mood said it was the Syrian people who were suffering the consequences of the failure to implement UN-Arab League envoy Kofi Annan’s peace plan. “There is no other plan on the table, yet it is not being implemented,” the veteran Norwegian peacekeeper said. “Instead there is a push towards advancing military positions.”

Major General Mood warned “this is not a static mission,” adding that the mission’s mandate would come under review by the UN Security Council at the end of next month.

On the ground, at least 15 people were killed in violence yesterday, including two demonstrators killed by regime forces in the northern city of Aleppo as thousands protested against the regime across Syria, a monitoring group said.

Eight people were killed in Busra al-Sham in an explosion outside a mosque in the southern province of Daraa, while another blast was reported in Al-Midan area of Damascus, without reports of casualties.

Regime forces also tried to reassert control over the central city of Homs and the town of Andan in Aleppo province, clashing with rebels and leaving two people dead in shelling, said the Syrian Observatory for Human Rights.

Human Rights Watch, meanwhile, accused Syrian government forces of having used sexual violence to torture men, women, girls and boys detained since the unrest broke out in March 2011.

The New York-based group said it had interviewed 10 former detainees, including two women, who described being sexually abused or witnessing such abuse in detention.