The Iranian navy boarded and briefly seized a Liberian-flagged oil tanker near the strategic Strait of Hormuz, the American military said Thursday, according to The Associated Press.

The US military's Central Command published a black-and-white video showing what appeared to be special forces fast-roping down from a helicopter onto the MT Wila, whose last position appeared to be off the eastern coast of the United Arab Emirates near the city of Khorfakkan.

The Iranian navy held the vessel for some five hours before releasing it Wednesday, said a US military official who spoke to AP on condition of anonymity to discuss details not yet made public. The Wila made no distress calls before, during and after the seizure, the official said.

The Iranian helicopter involved appeared to be a Sikorsky SH-3 Sea King, which only Iran's navy operates, according to the report.

The Iranian navy handles all operations in the Gulf of Oman on the eastern side of the Strait of Hormuz, through which 20% of all oil traded passes. Two other Iranian naval vessels took part in the seizure, Central Command said.

The International Maritime Security Construct, which is a US-created maritime group to protect Persian Gulf waterways, called the Iranian boarding “a blatant violation of international law that undermines freedom of navigation and the free flow of commerce.” It said one of its vessels “monitored the incident” but did not intervene.

Iranian state television later on Thursday acknowledged the brief seizure, referring to the operation as a routine inspection without elaborating.

This is not the first maritime incident involving Iran in the Strait of Hormuz. In the last few years there have been several close encounters between Iranian and American vessels in the area.

Iran regularly holds drills at the Strait of Hormuz, which is located at the mouth of the Persian Gulf and through which about a third of all oil traded at sea passes.

The Islamic Republic has threatened more than once to close the Strait of Hormuz, with the United States warning Iran in response that any attempt to close the strait would be viewed as a "red line" -- grounds for US military action.

In April, the US Navy said a group of 11 Iranian naval vessels made “dangerous and harassing” maneuvers near US ships in the Persian Gulf near Kuwait/

Iran’s Revolutionary Guard later acknowledged it had a tense encounter with US warships in the Persian Gulf, but also claimed that it was American forces who sparked the incident.