The pro-Iranian Lebanese Shiite movement Hezbollah has confirmed the death of three fighters following suspected Israeli airstrikes in Syria.
The group published the names of three members on Friday without providing further details, but Hezbollah sources confirmed to dpa that the fighters were killed in Syria.
Earlier, the Syrian Observatory for Human Rights, a war monitor documenting violence in Syria since 2011, said at least 42 people were killed in heavy air strikes carried out by Israel on the Aleppo province at dawn.
According to the British-based group, 36 Syrian army personnel and six members of Hezbollah were among the fatalities.
The attacks were concentrated on targets around the provincial capital of Aleppo. Israel's army said it did not wish to comment on the report.
Israel's air force repeatedly bombs targets in neighboring Syria in order to prevent Iran and its allied militias such as Hezbollah from expanding their military influence in the country.
Israeli attacks have increased since the start of the Gaza war at the beginning of October, when members of the Palestinian Islamist movement Hamas and others invaded Israel, killing some 1,200 people.
Still, the nearly four dozen deaths from early Friday is a rare, high figure for the conflict.