Five boats thought to be Iranian tried to stop a British oil tanker in the Strait of Hormuz, according to US officials. The boats withdrew after a warning from a British warship operating in the area. The incident comes as a Royal Navy warship was said to be offering extra protection to a second tanker in the Gulf following a threat from Iran to seize a British vessel. Sky News understands HMS Montrose, a Type 23 frigate, has been travelling with a tanker, British Heritage, according to a ship tracking website and a defence source. Tensions have been rising since...