Yemen's Houthi rebels say they have launched two attacks against Israel, vowing more.

Pro-Iran Houthi rebels said late on Saturday that they conducted a second missile attack targeting Israel, after officially joining the month-long war earlier in the day.

Houthi spokesman Yahya Saree said in a statement that the group fired "a barrage of cruise missiles and drones targeting several vital and military sites" in Israel, adding it "coincided with the military operations being carried out by" Iran and Hezbollah in Lebanon.

The Houthis vowed to continue military operations in the coming days.