The French navy has shot down two drones over the Red Sea where Yemen's Huthi rebels have been attacking ships, the defence ministry said Thursday, in the second such incident this week.

The navy, which has two frigates deployed in the area, detected a threat in the night of Wednesday to Thursday and "destroyed two drones", it said.

It said earlier this week it had downed two other drones overnight Monday to Tuesday.

On Monday, the European Union formally launched a naval mission to protect Red Sea shipping from the Iran-backed Huthis who control much of war-torn Yemen.

The rebels have been harassing the vital shipping lane since November in a campaign they say is in solidarity with Palestinians in Gaza during the Israel-Hamas war.

France's Languedoc previously shot down two drones in the Red Sea in self-defence in December, the foreign ministry has said.

The European Union aims to have its mission -- called Aspides, Greek for "shield" -- up and running in a "few weeks" with at least four vessels, an official said last Friday.

The United States is spearheading its own naval coalition in the area and has conducted retaliatory strikes on Huthi targets in Yemen, as has Britain.

The dozens of Huthi attacks have roiled shipping in the Red Sea, leading some companies to take alternative routes including a two-week detour around southern Africa.