The Lebanese health ministry said four Syrians were killed Thursday in an Israeli strike on the south, where Hezbollah and Israel have exchanged near-daily fire since the Gaza war began in October.
"The health ministry announces... four Syrian nationals were martyred" in an "Israeli strike" on the southern village of Shama, it said in a statement.
The ministry said the toll might rise once DNA tests had been carried out.
The strike also wounded five Lebanese nationals, it added.
Emergency services told AFP that the dead were farmer workers and part of the same family.
Plumes of smoke billowed from the site of the strike, which heavily damaged two nearby buildings and burnt a vehicle to a crisp, a photographer working with AFP reported.
Hezbollah has not claimed any new attacks since an Israel air strike killed its top commander Fuad Shukr on Tuesday evening, with leader Hassan Nasrallah saying operations will resume on Friday morning.
Nasrallah warned his group was bound to respond to the killing of Shukr.
His death was followed hours later Wednesday, by the killing of Hezbollah ally Hamas's chief Ismail Haniyeh in a strike in Tehran, which Iran and Hamas have blamed on Israel. Israel has declined to comment on his killing.
The violence since October has killed at least 542 people on the Lebanese side, most of them fighters but also including 114 civilians, according to an AFP tally.
At least 22 soldiers and 25 civilians have been killed on the Israeli side, including in the annexed Golan Heights, according to army figures.