A suicide vehicle bombing of an army checkpoint outside Damascus has killed 16 soldiers, Syrian activists say.
The state news agency Sana confirmed a blast today in the suburb of Jaramana and said it caused casualties.
The Britain-based Syrian Observatory for Human Rights said that rebels led by the al Qaida-linked Jabhat al-Nusra or Nusra Front, carried out the attack while trying to capture the checkpoint in the town of Mleiha, overlooking Jaramana. It reported heavy fighting after the blast.
Rebels control much of the countryside around Damascus but Jaramana, a Christian and Druse area, is mostly loyal to president Bashar Assad.
Assad has drawn support from Syria's ethnic and religious minorities, including Christians and members of his Alawite sect. The rebels are dominated by Syria's Sunni Muslim majority.
Meanwhile, nine Shiite pilgrims from Lebanon kidnapped in Syria were freed late last night as part of a negotiated hostage deal that could see two Turkish pilots held by Lebanese militants released, officials said.
The complicated three-way deal also potentially includes the release of female prisoners now held by the embattled Syrian government.
While details about the deal remained murky, it appeared to represent one of the more ambitious negotiated settlements to come out of Syria's civil war, now entering its third year and being fought by forces tearing apart the region and largely opposed to any bartered peace.
The pilgrims were part of a group of 11 hostages taken by a rebel faction in northern Syria in May 2012. Two were later released, but the nine had been held since, causing friction in the region and sparking the August kidnapping in Beirut that saw two Turkish Airlines pilots abducted.
Lebanese interior minister Marwan Charbel said that the nine Lebanese hostages "are now in Turkish territories".
He said he expects two Turkish pilots to be released in Lebanon soon and the Syrian government will release a number of female detainees.
"We insist that those who kidnapped the Turks release them," Mr Charbel said, referring to the pilots. The two pilots appeared in a video on Wednesday, the first since they were kidnapped.
"This is all part of one deal," he said.
Asked when he expects the freed Lebanese to come home, he said "in the coming 24 to 48 hours".
In Turkey, the state-run Anadolu Agency quoted foreign minister Ahmet Davutoglu as saying "there are positive developments" concerning the hostages and that the issue had "mostly been resolved".
The agency did not provide any further details, though a previous story said Turkish prime minister Recep Tayyip Erdogan called the wife of one of the kidnapped pilots to say the two would be released soon.
"We are very close to reaching a happy ending, this could happen any time," the agency quoted Mr Erdogan as saying.
The pilgrims were kidnapped in May 2012 while on their way from Iran to Lebanon through Turkey and Syria. Militants seized them shortly after they crossed the Turkish border into Syria. Two of the pilgrims were later released with Turkey's assistance.
In Beirut's southern suburbs, the families of the nine Lebanese gathered last night at the travel agency they went to Iran with, some of them weeping.
The two Turkish Airlines pilots, previously identified as Murat Akpinar and Murat Agca, were kidnapped after flying into Beirut from Istanbul on August 9.
Lebanon's state news agency reported that a group called Zuwaar al-Imam Rida claimed responsibility.
The group said the pilots "will only be released when the Lebanese hostages in Syria return," referring to the Shiite pilgrims.
The commander of the rebel brigade that kidnapped the pilgrims, Ammar al-Dadikhi, said last September that he was holding them captive to try to force Lebanon's Shiite militant group Hezbollah to stop supporting Assad's government.
Syria's rebels are predominantly Sunnis, and are widely supported by Lebanon's own Sunni community. Hezbollah fighters have played a critical role in recent battlefield victories for forces loyal to Assad.
Details about the negotiated deal remained vague last night, including who was responsible for co-ordinating across different factions in the Syrian civil war.
Satellite news channel Al-Jazeera quoted Qatar's Foreign Minister Khalid bin Mohamed al-Attiyah as saying the tiny Gulf nation negotiated the release of the nine pilgrims.
It also remained unclear what female prisoners the Syrian government would release under any potential deal.