BEIRUT (Reuters) - United Nations monitors in Syria have suspended operations because of the increasing violence over the last 10 days by President Bashar al-Assad's forces and rebels seeking his overthrow, the head of the observer mission said on Saturday.

"The observers will not be conducting patrols and will stay in their locations until further notice," General Robert Mood said in a statement.

Mood said the intensification in violence was impeding the 300 unarmed U.N. monitors from carrying out their mandate to observe an April 12 ceasefire deal, which has failed to halt the violence.

"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," Mood said.

Many hundreds of people, including civilians, rebels and government forces, have been killed in the two months since international mediator Kofi Annan's ceasefire deal was supposed to come into effect.

Last week shots were fired at a car carrying U.N. observers after they were turned away from the town of Haffeh by angry Assad supporters who threw stones and metal rods at their convoy, a spokeswoman for the monitors said.

(Editing by Louise Ireland)