WASHINGTON (Reuters) - Iranian military fast-boats in the Gulf of Oman are preventing two privately owned tug boats from towing away an oil tanker damaged in attacks on Thursday, a U.S. official said on Friday, speaking on condition of anonymity.

The U.S. official did not say how the United States knew of the reported standoff between the Iranian fast-boats and the tug boats, which were trying to tie up and tow away the Norwegian-owned Front Altair. The United States blames Iran for Thursday’s attacks against the Altair and the Japanese-owned Kokuka Courageous.

Tehran denies the accusations.