Activists say fighting and government shelling has stopped in Syria's central city of Homs in advance of an expected visit by UN observers.

Walid Fares of the Homs Revolutionary Council said the city has been calm for the last four hours but that tanks and artilleries remain in the streets. 

"There is no shelling whatsoever," Fares said.

"We believe that the calmness has to do with the arrival of the monitors. We wish they could live with us so that this peace can remain."