Iran tested a suicide drone against a practice vessel in the Persian Gulf region and fired one other missile or drone without warning ships in the area, a US official said.

The one-way drone was launched on Wednesday from the Jask area of Iran 8-9 miles out to sea - within Iran's territorial waters - against a practice barge, the official said, citing US intelligence data.

"Essentially practicing hitting merchant vessels. That's the only reason why you would do that in the Gulf of Oman," the official said.

The United States has accused Iran of being behind several attacks since 2019 against merchant vessels in strategic Persian Gulf waters, which contain some of the world's most important oil and shipping routes.

Iranian media have so far not reported, and officials have not commented on the development.

Iran periodically tests explosive or suicide drones and broadcasts footage of them being tested.

"The closest merchant vessel was about 30 miles out away from the barge, but it was still dangerous," the official said.

Iran has supplied hundreds of its Shahed 131 and 136 suicide drones to Russia that have been extensively used against Ukrainian military and civilian targets.

Early on Thursday Russia launched 20 of these drones against Ukraine but all were shot down before reaching their targets. One purpose of the Iranian drones that are much cheaper than long-range missiles, is to swarm Ukraine’s air defenses during missile attacks.

Reporting by Reuters