(Reuters) – Suicide bombers targeting Yemen’s powerful Shi’ite Houthi group and an army camp killed at least 67 people in two separate attacks on Thursday, hours after a political crisis forced the new prime minister to step down. At least 47 people were killed, including four children, when a suicide bomber detonated a belt packed with explosives at a Houthi checkpoint in the centre of the capital Sanaa where Houthi supporters were preparing to hold a rally.