Two of the world’s largest shipping firms, Maersk and Hapag-Lloyd, have said they are suspending passage through a Red Sea strait vital for global commerce, after Yemeni rebel attacks in the area, AFP reports.

The Iran-backed Houthis, who control much of Yemen but are not recognised internationally, say they’re targeting shipping to pressure Israel during its two-month-old offensive with Hamas in the Gaza Strip.

The maritime tensions have added to fears that the Gaza conflict could spread.

German transport company Hapag-Lloyd said it was halting Red Sea container ship traffic until December 18, after the Houthis attacked one of its vessels. “Hapag-Lloyd is interrupting all container ship traffic across the Red Sea until Monday,” the company said in a statement sent to AFP.

The Danish firm Maersk made a similar announcement, a little earlier. “We have instructed all Maersk vessels in the area bound to pass through the Bab al-Mandab Strait to pause their journey until further notice,” it said.