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 Eternity C, which also killed at least three of the crew, represents the most serious assault carried out by the Houthis in the crucial maritime trade route.

Israel’s military launched airstrikes early Monday targeting ports and facilities held by Yemen’s Houthi rebels, with the rebels responding with missile fire targeting Israel. The attacks came after an attack Sunday targeting a Liberian-flagged ship in the Red Sea that caught fire and took on water,