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.

Two Liberian-flagged ship attacks and a round of Israeli airstrikes early Monday targeting Houthi rebels raised fears of a renewed Houthi campaign against shipping.