“This escalation is limiting our ability to observe, verify, report as well as assist in local dialogue and stability projects – basically impeding our ability to carry out our mandate,” General Robert Mood, head of the UN Supervision Mission in Syria (UNSMIS), said in a statement.

“The lack of willingness by the parties to seek a peaceful transition, and the push towards advancing military positions is increasing the losses on both sides: innocent civilians, men women and children are being killed every day. It is also posing significant risks to our observers,” he added.

The Security Council established UNSMIS in April to monitor the cessation of violence in Syria, as well as monitor and support the full implementation of a six-point peace plan put forward by the Joint Special Envoy of the United Nations and the Arab League for the Syrian Crisis, Kofi Annan.

Gen. Mood said UN observers will not be conducting patrols and will stay in their locations until further notice, and that engagement with the parties will be restricted.

“This suspension will be reviewed on a daily basis. Operations will resume when we see the situation fit for us to carry out our mandated activities.”

He reiterated that UNSMIS stands ready to work with all parties to assist in bringing an end to the violence and promote political dialogue.

However, hundreds of people have been killed since the first observers were deployed in April and the mission has been harshly criticised by the opposition.

Syria’s foreign ministry said Mood had informed the government of the decision to temporarily reduce the work of the monitors, Syria’s official SANA news agency reported on Saturday.

“The ministry understands the decisions taken by General Robert Mood, particularly those related to preserving the safety of observers,” SANA’s report said.

The UN estimates that more than 10,000 people, mostly civilians, have been killed in Syria and tens of thousands displaced since the uprising against President Bashar al-Assad began some 16 months ago while activists put the number at more than 14000.

“Their mission is being obstructed by three factors: First, they are being stopped at Syrian Army checkpoints and in some cases turned back; second, some of our patrols are being stopped by civilians in the area; third, we are receiving information from residents of the area that the safety of our observers is at risk if we enter the village,” the head of the United Nations Supervision Mission in Syria (UNSMIS), Major-General Robert Mood, said in a statement.

“Despite these challenges, the observers are still working to get into the village to try to establish the facts on the ground,” he added.

According to media reports, Syrian activists claim that Government troops and militiamen massacred at least 78 villagers in Mazraat al-Qubeir, located near the city of Hama. UNSMIS dispatched observers to the site early Thursday.

The UN estimates that some 10,000 people, mostly civilians, have been killed in Syria and tens of thousands displaced since the uprising against President Bashar al-Assad began some 15 months ago.

In his statement, Major-General Mood also noted UNSMIS’ concern about the restriction imposed on its movement “as it will impede our ability to monitor, observe and report.”

The Security Council established UNSMIS in April to monitor the cessation of violence in Syria, as well as monitor and support the full implementation of a peace plan put forward by the Joint Special Envoy of the United Nations and the Arab League for the Syrian Crisis, Kofi Annan.

The plan calls for an end to violence, access for humanitarian agencies to provide relief to those in need, the release of detainees, the start of inclusive political dialogue that takes into account the aspirations of the Syrian people, and unrestricted access to the country for the international media.

Later today, Annan will brief the General Assembly in person, followed by the Security Council and the media, on the latest developments in Syria. Also speaking in the Assembly meeting will be President of the General Assembly, Nassir Abdulaziz Al-Nasser, Secretary-General Ban Ki-moon and the Secretary-General of the Arab League, Nabil Al Araby.

“I am more convinced than ever that no amount of violence can resolve this crisis durably. The Mission plans to help bring talks between parties on the ground on urgently needed stability,” he added.

The UNSMIS chief said that the Mission is on its way to full deployment, with some 260 military observers on the ground, hailing from 60 UN Member States, and that he expected the Mission to be fully operational soon, in “record time.”

In relation to the possible involvement of third parties, such as the terrorist group Al-Qaida, in the violence in Syria, the UNSMIS chief noted that there had been some “very worrying incidents”, such as deadly bomb attacks in Damascus on 10 May, which reportedly killed or wounded dozens.

“This is the kind of violence that is obviously impossible at this stage to decide where it came from, by whom,” he said. “I am concerned about incidents where explosive improvised devices are targeting innocent civilians, innocent people, because it is not going to help the situation. I have seen the reports that you refer to, if they are correct it is a worrying development.”

Speaking in Geneva, the spokesperson for Joint Special Envoy Annan, Ahmad Fawzi, told reporters that Mr. Annan has mentioned the involvement of a “third element” in the violence, which has led to further concerns.

“And when we speak about ‘third actors’ on the ground, we mean there are the hallmarks of activities and incidents and explosions that appear to come from sources other than opposition or Government sources. This has yet to be verified.”

Ban Ki-moon, the UN secretary-general, on Thursday said he believed last week’s deadly bombings in Damascus were the work of al-Qaeda, said the UN was still investigating who was responsible for the attacks which killed at least 50 people and injured hundreds.

On Friday Ban called again for all parties in the country to abide by a six-point peace plan proposed by UN-Arab League envoy Kofi Annan and said the UN was accelerating its deployment of its monitoring mission, according to Al Jazeera.

The crisis in Syria, which began in March 2011, has claimed over 9,000 lives, mostly civilians, and displaced tens of thousands.