U.S. embassy pulls out of Syria

>>> good evening. the united states has decided to close its ebassy and pull its people out of syria because it's increasingly clear the syrian government of president assad has decided to escalate the crackdown on the citizens' uprising there. the u.n. security council tried to do something about it this past weekend, but they were blocked by two know votes from syria 's friends russia and china. now the world tries to figure out what to do while it's increasingly clear what's going on inside syria . we begin our coverage with our own ayman mohyeldin who just emerged from syria .

>> reporter: mortars raining down on the city of homs with rocket and artillery fire . recovering dead bodies has become too dangerous for residents, who hey government snipers shoot to kill anyone who dares to step out no place is safe. not even this make-shift clinic where people seek refuge and doctors struggle to treat the injured. it, too, was hit.

>> all we want is help. we don't care how. we don't care if an army comes in. we don't care if the u.n. bombards syria to rescue us. we just want help.

>> reporter: but there is no help. a united nations security council resolution calling on president assad to begin turning over power was vetoed saturday by russia and china in the face of international condemnation.

>> the international community must protect the syrian people from this abhorrent brutality.

>> this is a doomed regime as well as a murdering regime.

>> reporter: russia 's foreign minister fired back calling comments indecent and bordering his teshgic. in syria , angry protestors burned russia and chinese flags .

>> it seems like the syrian government is treating the security council vetoes as a green light to step up the violence. it's a license to kill .

>> reporter: that's how many are explaining the sharp escalation of violence in homs. the city has been under siege for days. relentless bombardment pushed the death toll to more than 300. amateur footage shows what the people are up against. eye witnesses report syrian tanks and soldiers are moving to other cities, as well, a sign similar attacks in other parts of the country could be imminent. brian, 11 months into it, many are questioning how much longer the syrian military will continue to fight the protestors. the opposition force fighting the assad regime says more defectors are joining its ranks and it is looking for countries willing to supply it with more weapons. an indication that this is going to get a lot more violent before it ends. brian?

>> ayman mohyeldin with us from cairo. thanks.