Iran has threatened to “extend confrontation to US bases” in the region if Washington continues to urge ships to pass through the Strait of Hormuz. The Iranian military says its navy has struck four ships involved in oil transfers in the Gulf, and that three other vessels caught fire after hitting mines. The crisis around the Strait of Hormuz, combined with the Houthi attacks in Saudi Arabia have put significant pressure on global oil prices, which jumped by 3 percent on Thursday. Paul Hawkins reports.