Syria's largest opposition group, the Syrian National Council, says the latest bombardment of the city of Homs by presidential forces has killed at least 50 people.
Reuter's news agency quotes a senior member of the council, Catherine al-Talli, as saying the tally provided by activists around the city since the bombardment started at 6am stands at 50, with most of the casualties civilians.
In a broadcast from a BBC correspondent smuggled into the city, shelling and explosions can be heard and he reports that, at times, mortar shells were falling every 30 seconds.
The bombardment came a day after the United States promised harsher sanctions against Damascus.
It was responding to Russian and Chinese vetoes of a draft United Nations resolution that would have backed an Arab plan urging the president, Bashar al-Assad, to step aside.
