ROUGH CUT (NO REPORTER NARRATION).
Activist video posted to a social media web site purports to show heavy shelling in the battered Homs district of Khalidiya, where activists reported shelling at the rate of one per minute.
The footage appears shows an explosion shortly after the sound of a missile flying through the air. Another whiz follows and the cameraman, standing in a nearby building, pans across to show a ball of flames and smoke rising into the air.
Reuters is unable to independently verify the content of this video, which have been obtained from a social media web site.
Rami Abdelrahman, head of the British-based Syrian Observatory for Human Rights, said shells were being fired at a rate of one a minute. He said there had also been overnight clashes in rural Aleppo.
Syria blames the violence on "terrorists" seeking to topple President Bashar al-Assad and has repeatedly denied journalists access to the country, making it impossible to independently verify the reports.
Although violence has continued throughout the ceasefire, which has been in effect for four days, there has been a significant drop in the daily death toll from fighting, which in the past has killed more than 100 people a day.
On Saturday (April 14), 14 people were killed in the violence, Abdelrahman said and the state news agency SANA said "armed terrorists" killed five people in ambushes around the country.
A six-person advance party of United Nations (UN) observers is due to arrive in Syria to monitor the ceasefire -- meant to start four days ago.
