Yemen’s Iran-backed Houthis killed at least 58 government troops in missile and drone attacks on Thursday, a military source said, in one of the deadliest days of the country’s civil war in four years. The attacks come as Yemen is increasingly drawn into the US-Israeli war with Iran, with the rebels stepping up attacks against both government forces and neighbouring Saudi Arabia, a key US ally and supporter of the internationally recognised Yemeni government. Houthi military spokesman Yahya...