Iranian gunboats fired at a tanker in the Strait of Hormuz on Saturday, according to UK Maritime Trade Operations, following Tehran’s move to reinstate restrictions on the key shipping route.

The tanker's captain reported being approached 37 kilometers (23 miles) northeast of Oman by two gunboats of Iran's Revolutionary Guards Corp (IRGC). Without any radio warning, the gunboats "then fired upon the tanker", the UK Maritime Trade Operations Centre said in an online statement.

"Tanker and crew are reported safe. Authorities are investigating,” it reported, without identifying the vessel or its destination.

TankerTrackers.com reported vessels were forced to turn around in the strait, including an Indian-flagged super tanker, after they were fired on by Iran.

Iran's joint military command said on Saturday that "control of the Strait of Hormuz has returned to its previous state... under strict management and control of the armed forces."