Israel carried out it 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 commercial vessels targeted in 24 hours raise fears of an escalated campaign against Israel-linked shipping.