Syrian activists say the government is sending more troops to areas outside of the capital, Damascus, to carry out a large-scale security sweep.
Tuesday's move comes a day after the United States condemned the violence in Syria and urged President Bashar al-Assad's government to stop deadly actions against peaceful protesters.
The State Department said Monday the actions of Syria's security forces are "reprehensible" and include "barbaric shootings," torture and other human rights abuses.
Rights groups say Syrian forces have killed at least 1,600 civilians during a crackdown against more than four months of anti-government protests. The government has refused to accept blame for the violence and claims much of the unrest is caused by terrorists and Islamists.
Assad has made a series of overtures to try to ease the unrest, including lifting emergency laws and drafting a new law to allow the formation of political parties in addition to the ruling Ba'ath party.
Some information for this report was provided by AP.