Activists say rapid advances by Syrian government forces backed by Lebanese Hezbollah fighters south of the capital Damascus have slowed because of a snowstorm hitting the region.

Ahmad al-Masalmeh, an opposition activist in the southern city of Daraa, said snow fell Thursday in some areas south of Damascus, making it difficult for vehicles to move. He also said there was no government air force activity.

Syrian troops and Hezbollah fighters on Wednesday seized strategic hills and villages from rebels and a local al-Qaida affiliate near the Israeli-occupied Golan Heights in a surprise counteroffensive that alarmed Israeli officials.

Syrian TV said the offensive was continuing Thursday, but the Syrian Observatory for Human Rights said military operations were "limited" all over Syria because of the storm.