The Al-Quds Brigades, the armed wing of Islamic Jihad, said in a statement that three of its fighters "from the Syrian arena" were killed, while Lebanon's Hezbollah issued a statement saying a fighter was killed, without specifying where.

The Israeli air force "struck and eliminated... a significant terrorist in the Islamic Jihad terrorist organization’s operations division, in the area of the Syrian-Lebanese border," an Israeli military statement said.

Since Syria's civil war erupted in 2011, Israel has carried out hundreds of strikes in the country, mainly targeting army positions and Iran-backed fighters, including from Hezbollah.

Israeli authorities rarely comment on individual strikes in Syria but have repeatedly said they will not allow arch-enemy Iran to expand its presence there.

The Syrian Observatory for Human Rights, a monitor of the country's civil conflict, close to the Syrian opposition, said four people were killed in the incident.

The Britain-based Observatory, which relies on a network of sources inside Syria, said the attack occurred Wednesday morning "near a Syrian regime checkpoint on the Damascus-Beirut Road" as it was heading towards Lebanon.

Syrian state media have yet to report the incident.

Strikes claimed by or blamed on Israel have targeted vehicles in the Syria-Lebanese border area several times since October 7.

A Lebanese security source had said an overnight Israeli air strike hit a lorry loaded with Hezbollah missiles in eastern Lebanon near the Syrian border.

The Israeli military did not claim the strike.

Hezbollah has a strong presence in east Lebanon's Bekaa Valley, which borders Syria, and in south Lebanon, where it has been launching near-daily attacks on Israeli positions since October in support of ally Hamas.