Attacks by the Iran-aligned Houthis on a military camp in Yemen and in Saudi Arabia have sparked concerns that the Middle East crisis will continue to spiral.Yemen is being increasingly drawn into the US-Israeli war with Iran, with the Houthi rebels stepping up attacks against both government forces inside the country and neighbouring Saudi Arabia, a key US ally and supporter of the internationally recognised Yemeni government.On Thursday, at least 30 Yemeni government troops were killed in Houthi attacks on military ⁠camps in Yemen, government sources said, warning the death toll could rise. Some reports have put the death toll as high as 58.The ⁠Iran-aligned Houthis claimed they carried out the missile and drone strikes in Marib and Hadramout provinces after observing a large Saudi military build-up.The Houthis claimed military ‌camps, weapons depots and ‌vehicles were destroyed. Yemen’s defence ministry said in a statement only that its armed forces would respond to the attacks “at the appropriate place and time”, while the health minister ordered medical facilities to increase readiness to treat wounded soldiers.Yemeni sources said recently they believed Saudi Arabia was preparing for a major military offensive against the Houthis by sea and possibly by land in central Yemen, in a move to break their chokehold on Saudi oil exports through the southern Red Sea.In a separate attack early on Friday, a Saudi official accused the Houthis of indiscriminately shelling civilian areas in Saudi Arabia, injuring 11 civilians, including a four-year-old child. Maj Gen Turki al-Maliki, spokesperson for the Saudi-led military coalition supporting Yemen’s government, said the coalition would continue taking all necessary ⁠measures to protect civilians.The attack was in southern Najran province, and injured seven Saudis, one Yemeni, two Egyptians ⁠and one Pakistani national, he said.Neither the Houthis nor Iran immediately commented on Friday’s attack.Saudi Arabia and the Houthis have been vying for control of Yemen for more than a decade but over the past month an uneasy status quo has unravelled, with the Houthis mounting attacks against Saudi Aramco oil facilities.The Houthi movement, which controls Yemen’s capital Sana’a and much of its Red Sea coastline, declared a naval blockade of Saudi Arabia in the Red Sea last month.A senior ⁠Saudi official on Thursday said the kingdom was expecting imminent co-ordinated attacks from the north and ⁠south by Iraqi militias and the Houthis in Yemen under the supervision of Iran’s Islamic Revolutionary Guard Corps.The ​official, speaking on condition of anonymity, said intelligence reports from Saudi Arabia, the US and other regional ⁠countries indicated civilian and economic sites could be targeted, including energy infrastructure, ports and airports.Saudi Arabia had also observed ⁠drones and missiles being moved, suggesting co-ordinated operations from both directions, the ​official said.It comes as Iran and Oman said negotiations on an agreement over the Strait of Hormuz was in its “final stage” of drafting. The agreement is likely to be contingent on the US lifting its blockade on Iran’s ports.The strait is crucial to global shipping and energy supplies. Before the war, which began with US and Israeli strikes on Iran in February, about a fifth of the world’s traded oil and natural gas passed through the waterway at the mouth of the Gulf. – Guardian with Reuters, Associated Press and Agence France Presse