Heavy bombardment of the Syrian city of Homs resumed Tuesday after almost 100 civilians were killed Monday in an offensive to put down a popular revolt against President Bashar al-Assad's rule.

The Syrian army started firing artillery at about 06:00 local time (04:00 GMT) Tuesday.

The bombardment is again concentrating on Bab Amro. A doctor tried to get in there this morning but I heard he was wounded, activist Mohammad al-Hassan was quoted as saying by Reuters.

There is no electricity and all communication with the neighborhood has been cut, he added.

Assad needs to look strong in front of the Russians. He has not managed to control Homs since the eruption of the uprising and now that he has seen that he faces no real threat from the international community it appears that he wants to finish off the city, Catherine al-Talli, a senior member of the opposition Syrian National Council, was quoted as saying by Reuters.

There are live television feeds from Bab Amro and the whole world can see indiscriminate shelling of civilians. This has not stopped him, he added.

Russian Foreign Minister Sergei Lavrov was in Homs to meet Assad in Damascus Tuesday. The supporters of Assad's welcomed Lavrov by waiving flags when the Russian Foreign Minister's car passed through the city.

Russia is the main supplier of arms to Damascus since the Syrian port of Tartus is the Russia's only Mediterranean naval base.

Our fears have come true, German U.N. ambassador Peter Wittig was quoted as saying by BBC.

Assad used the situation once again as a licence to kill - that's the sad aftermath of the veto, he added.