The US Navy shot down at least two Iranian drones in the Strait of Hormuz last week, the head of US Central Command said on Tuesday. The <em>USS Boxer </em>brought down the two drones in a nine-hour manoeuvre between the Arabian Gulf and the Gulf of Oman, Gen Kenneth McKenzie told <em>CBS News.</em> "As always, it was a complex tactical picture," Gen McKenzie said. "There may have been more that we are not aware of." He said the <em>Boxe</em>r engaged the two drones within an hour. The first moved in too close to the US vessel, forcing the warship to take action. Iran claimed that none of its drones were brought down in the Strait of Hormuz last week. At first, Tehran responded to US statements by saying the Americans appeared to have shot down one of their own unmanned vehicles. But<em> </em>before Gen McKenzie's announcement, a senior US official confirmed that the warship might have hit a second drone. “We brought down one for sure. There might have been a second,” the official said. There have been months of increasing tension between Iran, the West and its Arab allies. In June, Washington was set to launch military strikes against Iran after a US drone was destroyed. US President Donald Trump tweeted that he halted the strikes at the last minute because of the high number of casualties they would have inflicted. On Monday, Iran's semi-official Fars news agency published pictures of the crew of the British-flagged tanker the <em>Stena Impero </em>being held on their vessel. The ship was seized by Iran’s Islamic Revolutionary Guard Corps on July 19 in Omani waters, in retaliation for the earlier detention of an Iranian tanker by the British authorities in Gibraltar. The <em>Grace 1 </em>was stopped on suspicion that its cargo of oil was destined for Syria, in a breach of EU sanctions.