An opposition monitoring group says air strikes by the Syrian military have killed at least 20 people in the northwestern Latakia Province.
The Britain-based Syrian Observatory for Human Rights said on August 10 that the overnight air strikes hit the town of Salma.
Syrian opposition activists say Salma is a predominantly Sunni Muslim town in northwestern Syria, which is considered the heartland of President Bashar al-Assad's minority Alawite sect.
Alawites are a sect of Shi'ite Islam.
The attack is part of a push by Assad's forces to regain control of several Alawite villages in the mountainous Mediterranean coastal region. The rebels overran the region earlier this week.
Assad controls much of southern and central Syria, while insurgents hold northern areas near the Turkish border and along the Euphrates River valley.
The United Nations says more than 100,000 people have been killed in the 28-month conflict and 1.7 million Syrians have fled the country.
But opposition rights watchdog Syrian Observatory for Human Rights has warned that the real death toll could be twice as high.
The Britain-based group said on August 10 it had documented the deaths of more than 106,000 people, but said it estimated the real figure could be "double the figure documented by the Observatory due to extreme secrecy that both sides in the conflict maintain on their casualties."
On August 9, Russian Foreign Minister Sergei Lavrov said after talks in Washington that he and U.S. Secretary of State John Kerry had agreed on the need to start a Syrian peace conference in Geneva
as soon as possible.
Syria's 29-month old conflict has taken on an increasingly sectarian tone in the last year, pitting predominantly Sunni Muslim rebels against the Alawite-dominated regime and its Shi'ite allies in Lebanon and Iran.
The Sunni rebels are supported by Saudi Arabia and other Gulf Arab states.
With reporting by AFP and Reuters