Houthi rebels in Yemen have launched attacks on cargo ships in the Red Sea, raising fears of renewed conflict in the vital shipping corridor.

Israel has carried out its first strikes against Houthi targets in Yemen since the Israel-Iran ceasefire, attacking ports and a power plant around midnight local time Sunday night into Monday morning.

The attack on the Magic Seas, a dry bulk carrier owned by Greece’s Stem Shipping, was the first on a commercial vessel since December by the group, which is backed by Iran. It was followed almost immediately by Israeli strikes on a number of Houthi-held ports in Yemen.