United Nations: The United Nations will move about half of its 100 foreign staff members out of Syria after a number of mortar shells fell near their hotel in Damascus, damaging the building and a UN vehicle, the United Nations said on Monday.

UN spokesman Martin Nesirky said another 800 local UN staff had been asked to work from home until further notice.

“The United Nations Security Management Team has assessed the situation and decided to temporarily reduce the presence of international staff in Damascus due to security conditions,” Nesirky said.

Syrian rebels lobbed mortar rounds into central Damascus on Monday, killing at least two people and drawing a fierce army response as bombardments shook the capital.

“The United Nations remains active and committed to helping the Syrian sides in their search for a political solution,” Nesirky said. “UN agencies and partners also remain committed to providing assistance to millions of people in need in Syria.”

The two-year conflict began as peaceful protests that turned violent when Syrian President Bashar Al Assad tried to crush the revolt. The United Nations says more than 70,000 people have been killed and nearly 1.2 million have fled the violence.

Nesirky said mortar shells had landed on the grounds of the hotel in Damascus housing UN staff on Sunday and Monday.

He said the international staff worked for peace mediator Lakhdar Brahimi, the resident UN coordinator, the UN children’s agency Unicef, the Office for the Coordination of Humanitarian Affairs, the World Food Program and the United Nations Relief and Works Agency for Palestine Refugees UNRWA.

“There will still be in country enough people to be able to continue and indeed to increase the range of work particularly to reach people with food aid,” Nesirky said.

The UN Security Council has been deadlocked on Syria since 2011. Russia and China have refused to consider sanctions on Al Assad’s government and have vetoed three resolutions condemning Al Assad’s crackdown on opposition groups.

The United Nations said on Thursday it would investigate Syria’s allegations that rebel forces used chemical weapons in an attack near Aleppo, but Western countries are seeking a probe of all claims concerning the use of such banned arms.

US and European officials say there is no evidence of a chemical weapons attack. If one is confirmed, it would be the first use of such weapons in the Syrian conflict.