Syrian government troops launched Friday a counter- attack against rebels who have been inching closer toward Damascus, activists said, dpa reported.
"Syrian troops backed by tanks started in the early hours of Friday pounding rebel-held areas on the outskirts of Damascus," Haytham al-Abdullah, a Syrian activist based in the capital, told dpa.
He added that the offensive targeted mainly the suburban towns of Daraya and Maazamiyet al-Sham.
The state Syrian news Agency SANA said government troops in Daraya were pursuing "terrorists" from Al-Nusra Front, a rebel group fighting mainly in and around Damascus.
The Syrian opposition has called for nationwide protests on Friday.
News from Syria is hard to independently verify as authorities have barred most foreign media from the country since a pro-democracy started in March last year.
In Jordan, UN chief Ban Ki-moon visited a border camp sheltering Syrian refugees.
He is expected later in the day in Turkey where he will visit another camp for Syrian refugees and hold talks with Turkish leaders.
Meanwhile, three more people were killed in clashes between opponents and supporters of Syrian President Bashar al-Assad al-Assad in the northern Lebanese town of Tripoli, raising the death toll in sectarian violence there to 12 since Tuesday.