Syrian government forces have fired surface-to-surface missiles and conducted airstrikes on the rebel-held northwestern city of Idlib, killing more than a dozen rebels.
The Britain-based Syrian Observatory for Human Rights and the Local Coordination Committees said the Monday night strikes killed at least 14 people.
The attacks come amid fears that the government is preparing to retake the city that it lost on Saturday.
Idlib, with a population of around 165,000 people, became the second provincial capital to fall to the opposition after Raqqa, which is now a stronghold of the Islamic State group.
Its capture by several factions led by the al-Qaida-linked Nusra Front underscores the growing power of extremist groups in Syria, which now control about half the country.