Dozens of Syrian tanks and armored vehicles on Tuesday surrounded villages in the province of Idlib, near the border with Turkey, Arab media said, citing eyewitnesses and rights activists.
Reports said at least two people had been killed in clashes with troops. Injuries and arrests were also reported.
The development came as Turkish Foreign Minister Ahmet Davutoglu arrived in Syria to demand an end to a crackdown on protests by President Bashar al-Assad's government.
Syrian state media earlier said troops had withdrawn from Hama, the focus of a bloody crackdown of protestors.
The United Nations stepped up pressure on the Syrian government on Wednesday, condemning "the widespread violations of human rights and the use of force against civilians by the Syrian authorities" in a UN Security Council presidential statement.
The government intensified its crackdown on protesters with the beginning of the holy Islamic month of Ramadan, fearing that the dissent would use massive daily prayers at mosques to organize larger protests.
On Saturday, after a week of bloody government crackdown on protesters, the six-nation Gulf Cooperation Council urged the Syria authorities to "refrain from the excessive use of force" and launch "serious reforms guaranteeing full civil rights to the Syrian people."
The statement came as part of growing international pressure on the Assad regime, including the strongest ever condemnation of the violence in Syria by the Arab League, which was issued on Sunday.
