Syrian security forces have launched new raids, as the U.N. Security Council prepares to discuss the country's unrest.
Rights groups say at least one civilian was killed and three wounded on Wednesday after tanks moved into several northwestern villages near the Turkish border.
Meanwhile, witnesses say security forces have pushed further into Deir el-Zour, an eastern town that has been under siege for several days.
Syrian President Bashar al-Assad has been facing growing international condemnation for his crackdown on dissent.
The U.S. Wednesday announced new sanctions against Syria, freezing the U.S. assets of a bank and a mobile phone operator. The U.S. Treasury Department said both the Commercial Bank of Syria and Syriatel are part of the financial infrastructure that has been enabling what he called the Syrian regime.
Later Wednesday, the Security Council is set to meet to discuss possible further action against Damascus. Last week the Council issued a strong statement condemning the government crackdown on opposition protesters and calling for the violence to stop.
Also, a delegation consisting of Security Council members India, Brazil and South Africa met with Syria's foreign minister, Walid Moallem, on Wednesday in a move to halt the crackdown. The state-run SANA news agency says the foreign minister blamed "armed groups" for recent deaths and what he called acts of sabotage.
In a separate development, Turkish Prime Minister Recep Tayyip Erdogan said Wednesday a Turkish envoy had visited the flashpoint city of Hama, which had been under siege since late July.
He says Syrian security forces have begun to pull out of the city and expressed hope that the government would begin to enact reforms in the near future. His comments come a day after Turkey's foreign minister, Ahmet Davutoglu, met with Assad in Damascus and urged him to end the bloodshed.
A state-run news report says army units left Hama after restoring stability. The report said "armed terrorist groups" were responsible for the violence. Rights groups and activists say more than 100 people were killed in Hama during the government siege.
Assad has defended his crackdown on dissidents, saying it is a national duty to deal with what he called "outlaws" who block roads and "terrorize" people.
On Tuesday, the United States said Assad had made "horrible choices" in Hama and Deir el-Zour. State Department spokeswoman Victoria Nuland also said it is "deeply regrettable" that Assad does not seem to be hearing the "increasingly loud voice of the international community."
Russian Foreign Minister Sergei Lavrov spoke by phone to his Syrian counterpart, Walid Moallem, on Tuesday and urged him to find ways to end the violence and enact political reforms. Iraq's parliament also urged Syria to end the bloodshed, and Jordan and Egypt expressed concern about the unrest.