Flights to Beirut by Air France and low-cost carrier Transavia France will remain suspended until at least Tuesday due to "security" concerns in the region, parent company Air France-KLM said.

The two French airlines first stopped servicing the route on Monday, a day after Israel vowed to retaliate following rocket fire from Lebanon that killed 12 people in the Israeli-annexed Golan Heights.

"Any resumption of operation will be subject to a renewed evaluation on the ground," a spokesman said on Saturday, adding that passengers with reservations could rebook at no extra cost.

Flights to Tel Aviv will continue as normal, he added.

The rocket attack on the Golan Heights sparked fears that fighting between Hezbollah and Israel would escalate.

When those fears subsided somewhat the airlines announced on Tuesday that flights would resume on Wednesday.

But Israel then struck a Hezbollah stronghold in south Beirut on Tuesday evening, targeting a senior commander it blamed for the rocket strike on the Golan Heights.

This development sparked an extension of the flight suspension until Saturday, which has now been prolonged again.

Iran said earlier on Saturday it expects the Tehran-backed Hezbollah group to hit deeper inside Israel and no longer be confined to military targets.

German carrier Lufthansa, meanwhile, has suspended flights until August 5. (AFP)