Factbox-Who are Yemen’s Houthis and why did they attack Israel?

Yemen's Houthis have joined the Israel-Hamas war raging more than 1,000 miles from their seat of power in the Yemeni capital of Sanaa, declaring on Oct. 31 they had fired drones and missiles at Israel in attacks that highlight the regional risks of the conflict. In the late 1990s, the Houthi family in far north Yemen set up a religious revival movement for the Zaydi sect of Shi'ite Islam, which had once ruled Yemen but whose northern heartland had became impoverished and marginalised. As friction with the government grew, they fought a series of guerrilla wars with the national army and a brief border conflict with Sunni powerhouse Saudi Arabia.