Syrian troops have moved into two northern towns - Maarat al-Numan and Khan Sheikhoun - on the road between Damascus and Aleppo.
The BBC reports the troops are travelling on tanks, armoured personnel carriers and buses.
The move came as state television said President Bashar al-Assad's cousin, Rami Makhlouf, intends to give up his business interests and donate his profits to charity.
Mr Makhlouf is a powerful economic figure in Syria, with the BBC saying he has been the subject of persistent accusations of corruption and cronyism.
Protesters in Syria have specifically targeted his business interests, which cover telecommunications, construction and oil. He owns the country's largest mobile phone company.
Meanwhile, United Nations Secretary-General Ban Ki-moon has urged Syria to halt the bloodshed and "stop killing people".
The UN says that at least 1100 people have died as the government has violently sought to quash protests over the past three months.