Rebels stormed a prison and freed some 300 prisoners in north-west Syria, activists said Saturday, while government troops attacked rebel-held areas near the capital and discovered three tunnels for smuggling weapons, DPA reported.
The Britain-based Syrian Observatory for Human Rights posted a video showing what it claimed was the release of prisoners in Idlib.
Syria's pro-government television stations said heavy fighting was still raging near the vicinity of the prison. Quoting a source in the area, al-Dunia television reported that army reinforcements have been sent to the prison, and that all communications with the facility have been cut off.
Elsewhere, activists in Damascus reported a car bomb blast in the al-Zahira neighbourhood. They said they were unable to give report on casualties, as troops immediately cordoned off the area.
Government buildings have increasingly become targets in Syria.
Syria's official television broadcaster reported that government troops raided several rebel-held regions near the capital and uncovered at least three tunnels which were used by opposition fighters to smuggle weapons.
The state-run Syrian News Agency, SANA, said that tunnels were discovered near Daraya, south of the capital.
Syrian troops have been trying to capture Daraya for weeks, but have faced strong resistance from hundreds of rebels holed up in the area.
Daraya is a strategic area for the regime, as it is close to a major military air base.
Activists on Saturday said at least 85 people were killed in violence across Syria, among them 11 children, in an air raid in the northern province of Aleppo.
Also Saturday, a statement posted on the NATO website said the first of six Patriot missile batteries which were deployed to protect Turkey from Syrian threats were operational along the two countries' shared border.
"The battery, provided by the Netherlands, will help to protect the city and people of Adana (southern Turkey) against missile threats," the statement said.
NATO decided in December to deploy the batteries upon Turkey's request. In October, Syrian artillery shells hit the Turkish border town of Akcakale, killing five people.
Meanwhile, a senior Iranian government official said Saturday any foreign attack upon Syria would be considered an attack upon Iran itself.
"A military attack against Syria would also be an attack against Iran. Syria is, in the region, part of a golden ring of resistance (against Israel). For this reason, an attack on Syria would be considered an attack on Iran and Iran's allies," said Ali Akbar Velayati, an aide to Supreme Leader Ayatollah Ali Khamenei, according to the Mehr news agency.
Iran is a key ally of Syrian President Bashar al-Assad and considers Damascus part of an axis of opposition to Israeli and Western influence in the Middle East.