Yemen ’s Iran-backed Houthi rebels, who claimed responsibility for devastating weekend attacks on Saudi oil facilities, threatened on Monday to carry out more strikes and urged foreigners to stay away. “We assure the Saudi regime that our long hand can reach any place we want at any time we choose,” Houthi military spokesman Brigadier General Yahya Saree said in a statement. Strikes on two Saudi facilities on Saturday halted half the kingdom’s oil production and sent shock waves through energy markets. The US has blamed Iran for the attacks , saying there was no evidence they were launched from Yemen. The Houthis, who captured the Yemeni capital Sanaa in 2014, have been fighting against a Saudi-led coalition that intervened the following year in support of the internationally recognised government. Drone strikes in Saudi Arabia ‘may push China to diversify oil supply’ The rebels have repeatedly targeted key Saudi infrastructure in the past several months with explosive-laden drones. Saree said the weekend attacks were carried out with a new type of drone. “We warn companies and foreigners not to stay in the plants that we have targeted because they are still within our reach and could be targeted again,” he said. The Houthis claimed a drone strike on two oil pumping stations on Saudi Arabia’s vital east-west pipeline in May, forcing a days-long shutdown. Weeks later, they hit Shaybah oilfield, one of the largest in the kingdom, which pumps some one million barrels per day. Saudi Arabia has so far not accused any party of carrying out Saturday’s attacks, but said authorities have launched an investigation to determine the culprits. Oil prices surged by 20 per cent on Monday – the biggest intraday gain since the 1991 Gulf War – after the weekend attacks on the world’s top crude exporter, fuelling fresh fears of regional turmoil and economic chaos.