UPDATE 1-Fire on vessel off Dubai coast dies down - Reuters witness

A fire that had broken out on a vessel off the Dubai coast on Friday has died down, according to two Reuters witnesses.

A thick black column of smoke that appeared to engulf a ship or boat was visible at a distance from the beach near the ultra-luxurious Burj al-Arab hotel, they said. It was not clear how large the vessel was. The smoke dissipated about an hour after it was first reported in social media postings.

There was no comment from the authorities about the fire, which comes at a time of high tension between Iran and the United States. "The smoke has died down but still looks bad. Lots of boats around it now and heading towards it," said a posting on Twitter. "I've seen helicopters and a boat head in its direction."