DUBAI/WASHINGTON--The United States on Friday blamed Iran for attacks on two oil tankers at the entrance to the Gulf and said it was seeking international consensus about the threat to shipping, despite Tehran denying involvement in the explosions at sea.


  Thursday's attacks raised fears of a confrontation in the vital oil shipping route at a time of increased tension between Iran and the United States over U.S. sanctions and military moves in the Middle East, Tehran's proxy groups in the region and its nuclear programme.
  "Iran did do it and you know they did it because you saw the boat," U.S. President Donald Trump told Fox News.
  He was referring to a video released on Thursday by the U.S. military which said it showed Iran's Revolutionary Guards were behind the blasts that struck the Norwegian-owned Front Altair and the Japanese-owned Kokuka Courageous in the Gulf of Oman, at the mouth of the Gulf. Iran said the video proved nothing and that it was being made into a scapegoat. "These accusations are alarming," Foreign Ministry spokesman Abbas Mousavi said.
  Iran has dismissed earlier U.S. charges that it was behind the attacks and has accused the United States and its regional allies such as Saudi Arabia and the United Arab Emirates of "warmongering" by making accusations against it.
  Last month, the United States sharply tightened economic sanctions that are damaging the economy of Iran, which in response has threatened to step up its nuclear activity. Tehran has said it could block the Strait of Hormuz, the main route out for Middle Eastern oil, if its own exports were halted.
  Trump, who last year pulled the United States out of an agreement between world powers and Tehran to curb Iran's nuclear programme in exchange for some sanctions relief, said any move to close the Strait of Hormuz would not last long but added that he was open to negotiations with Iran. Iran has repeatedly said it will not re-enter talks with the United States unless it reverses Trump's decision to withdraw from the 2015 nuclear deal.
  Tehran and Washington have both said they have no interest in starting a war. But this has done little to assuage concerns that the two arch foes could stumble into a conflict.
  A U.S. official told Reuters on Friday a surface-to-air missile was fired from Iranian territory on Thursday morning at a U.S. drone that was near Front Altair following the attack on the tanker. The missile did not hit the drone, the official said.
  Trump's administration is focused on building international consensus following the attacks, U.S. Defense Secretary Patrick Shanahan said.
  Asked whether he was considering sending more troops or military capabilities to the Middle East, Shanahan said: "As you know we're always planning various contingencies."
  But he emphasized the issue of building consensus. "When you look at the situation, a Norwegian ship, a Japanese ship, the Kingdom of Saudi Arabia, the UAE, 15 percent of the world's oil flows through the Strait of Hormuz," he said.
  "So we obviously need to make contingency plans should the situation deteriorate. We also need to broaden our support for this international situation," he told reporters.
  Oil prices rose about 1% on Friday, reflecting the jitters. Insurance costs for ships sailing through the Middle East have jumped by at least 10% after the attacks, ship insurers said.
  U.N. Secretary-General Antonio Guterres called for an independent investigation of the attacks. The tanker attacks took place while Prime Minister Shinzo Abe of Japan - a big buyer of Iranian oil until it was forced by the new U.S. sanctions to stop - was visiting Tehran on a peacemaking mission, bringing a message from Trump.
  Iran dismissed Trump's message, details of which were not made public. "I do not see Trump as worthy of any message exchange, and I do not have any reply for him, now or in future," Iranian Supreme Leader Ali Khamenei said.