A German warship shot down two drones in the Red Sea on Tuesday amid escalating attacks by Yemen’s Houthis and efforts by the European Union to protect international shipping, German officials said.

Shipping risks have increased due to repeated strikes by the Iran-aligned Houthis in the Red Sea and Bab al-Mandab Strait since November in what they describe as acts of solidarity with Palestinians against Israel in the Gaza war.

U.S. and British forces have responded with several airstrikes on Houthi facilities but have so far failed to halt the attacks.

The German navy frigate Hessen, which was deployed earlier this month to the region, shot the drones down within 20 minutes of each one being fired, a defence ministry spokesperson told a news briefing, declining comment on the target of the projectiles.

“They were recognised by the radar system and had a different range. That’s why two different weapons were used,” the ministry spokesperson said.

The warship identified a suspicious drone on Monday but was unable to shoot it down successfully, the spokesperson added.

France, Greece and Italy are among countries that will participate in the EU mission that initially will see three vessels under EU command.

Participating countries will be mandated to protect commercial ships and intercept attacks, but not take part in strikes against the Houthis on land.

“This is … probably the most dangerous deployment of the German navy for many, many years,” a German government spokesper-son told the briefing separately.

The Houthis, who control Yemen’s most populous regions, sent shipping officials and insurers formal notice of what they termed a ban on vessels linked to Israel, the U.S. and Britain from sailing in surrounding seas.

The ban and the ongoing attacks may lead to an expansion of the areas deemed unsafe for sea navigation, further restricting insur-ance capacity and increasing premiums for vessels operating in or near these areas, Sebastian Hov, CEO of 18 Insurance, told Reu-ters.

“The increased insurance costs, along with the diversion of ships to longer routes to avoid high-risk areas, will strain global supply chains,” he said.

There was no update on the fate of the abandoned cargo vessel Rubymar after it was hit by a Houthi missile on Feb. 18 in the south-ern Red Sea and was leaking fuel. The vessel remains submerged with water amid fears it will sink.

Source: Reuters reported by Rachel More in Berlin, Jonathan Saul and Sinead Cruise in London and edited by Nick Macfie