Washington, May 11 (IANS): The Pentagon said that a US Coast Guard ship fired warning shots during a close encounter with vessels belonging to the Iran's Islamic Revolutionary Guard Corps Navy (IRGCN) in the Strait of Hormuz.

Addressing a briefing on Monday, Pentagon spokesman John Kirby said that six US Navy vessels escorting the USS Georgia, a guided missile submarine, encountered 13 IRGCN fast attack boats while transiting through the Strait of Hormuz earlier in the day, reports Xinhua news agency.

He said the Iranian boats approached the US formation at high speed, closing in as close as 150 yards (about 137 metres).

The US Coast Guard Cutter Maui fired about 30 warning shots from a machine gun before the Iranian boats left, Kirby added.

This was the second such encounter in two weeks.

In April, a US Navy patrol ship fired warning shots as IRGCN vessels approached to an "unnecessarily close range" in international waters of the northern Persian Gulf.

The incident came days after the US Navy seized an illicit shipment of weapons, including thousands of small arms and dozens of anti-tank guided missiles, from a stateless dhow in the North Arabian Sea.

An anonymous official told US media that the Navy's initial investigation indicated the vessel came from Iran.

The incident also came amid indirect talks between the US and Iran in Vienna to revive the 2015 nuclear deal, formally known as the Joint Comprehensive Plan of Action.