Washington, Apr 16 (IANS): The US Navy has accused Iran's Islamic Revolutionary Guard Corps (IRGC) of "dangerous and harassing approaches" in the Persian Gulf.

Eleven IRGC Navy vessels repeatedly conducted "harassing" approaches of six US Navy and Coast Guard ships on Wednesday, it said.

One passed within 10 yards (9m) of a Coast Guard cutter. The US vessels were involved in a military exercise with US Army Apache attack helicopters.

There has been no word yet from Iran.

The incident came a day after armed men - believed to have been IRGC personnel - seized a Hong Kong-flagged tanker in the Gulf of Oman and redirected it into Iranian waters before releasing it, the BBC reported.

The US Navy said "The US crews issued multiple warnings via bridge-to-bridge radio, five short blasts from the ships' horns and long-range acoustic noise maker devices, but received no response from the IRGCN."

"After approximately one hour, the IRGCN vessels responded to the bridge-to-bridge radio queries, then manoeuvred away from the US ships and opened distance between them," it added.

Tensions between the US and Iran rose further in January, when the US killed a top IRGC general in a drone strike in Iraq. Iran responded by launching missiles at Iraqi military bases hosting US forces.