Iran has seized another vessel and its crew in the Strait of Hormuz, a semi-official Iranian news agency reported on Monday.
Fars News said that the vessel was carrying "smuggled diesel" and that its crew of 11 had been arrested.
"The ship, called Linch, sailed from the port of Lankah and was heading towards the UAE. It was stopped 20 miles east of the island of Tunb," an Islamic Revolutionary Guard Corps naval commander told the agency.
The islands of Abu Musa and the Greater and Lesser Tunb, a few kilometres off the UAE coastline and regarded as strategically important waypoints in the Strait of Hormuz, were seized by Iran in 1971 as the UAE was formed.
If the ship seizure is confirmed, it would represent the latest move by Iran to hamper navigation in the waterway, one of the most vital routes for global energy supplies.
The US has blamed Iran for a series of attacks on oil tankers. Iran has seized at least one British-flagged tanker and approached another.
Washington and other Western powers have accused Tehran of lashing out after the US withdrew from the nuclear deal signed in 2015.
It then imposed two rounds of crippling sanctions on the Iranian economy to disrupt what it says is malign activity across the Middle East. Iran has proxies operating in Lebanon, Yemen, the Gaza Strip and Syria.