Syrian rebels pushed towards two military airports in the northern province of Aleppo on Saturday, a day after capturing a similar strategic military base, activists told dpa.
"Heavy fighting is taking place between rebels and troops manning Al-Ming military airport in Aleppo's countryside, resulting in many casualties in government forces ranks," said Abu Omar al-Halabi, a commander in the Free Syrian Army (FSA).
Rebels were also targeting Aleppo's Nairib military camp, he added.
Opposition fighters have captured the Tfatanaz northern military base, which had been used by the government to bomb opposition strongholds in northern areas of the country.
As fighting raged in the northern sector of the country, a senior intelligence officer announced his defection from President Bashar al-Assad's government in a video posted online by activists.
"I, Jumaa Farraj Jassem, the head of Section 30 of the foreign service of the General Intelligence Directorate, announce my defection from this criminal regime, and joining the blessed revolution," he said.
Activists inside Damascus confirmed the identity, but an information ministry source played down his rank and said that he is "a regular officer and not one of the main intelligence officers."
In the northern Idlib province, five soldiers were killed and 10 wounded in a bomb blast near their military truck on the Ariha-Sarraqeb road.
Following a three-day snow storm on Damascus, jets resumed their strikes on rebel-held areas at city's outskirts, killing at least five people, according to activists.
The Britain-based Syrian Observatory for Human Rights said warplanes and helicopters struck areas in Daraya, Mleiha and other areas in the farmland areas near Zabadani.
The 22-month Syrian conflict has claimed the lives of more than 60,000 people, according to UN estimates.
Russia called on Saturday for the launch of a political transition process in Syria, as Russian Deputy Foreign Minister Mikhail Bogdanov met with Syrian opposition members in Geneva, the Interfax news agency reported.
Bogdanov met with UN-Arab League special envoy Lakhdar Brahimi and US Deputy Secretary of State William Burns on Friday.
Moscow said it welcomes continuing consultations on Syria, although Brahimi has said he does not expect a political solution to end the 22-month Syrian conflict.
In Beirut, dozens of Lebanese, loyal to the western-backed March 14 movement, demonstrated in front the Syrian Embassy, describing the Syrian Ambassador to Lebanon, Ali Abdul-Karim Ali, "persona non grata" and called on him not to interfere in Lebanese internal affairs.
Lebanon's Foreign Minister Adnan Mansour, who is scheduled to chair the Arab League Ministerial Council meeting in Cairo on Sunday, is due to ask for 180 million dollars from Arab countries to assist Syrian refugees who have fled to Lebanon.
The UN High Commissioner for Refugees (UNHCR) said Friday that the number of Syrians who have fled to neighbouring countries and North Africa has jumped by more than 100,000 in the past month to 612,000.