U.S. Navy ships fire warning shots at Iranian vessel in Persian Gulf

U.S. warships fired several warning shots at Iranian vessels in the Persian Gulf for the second time in a week, which Tehran describes as another "provocative and unprofessional move."

The USS Nimitz and a second American ship dispatched a helicopter near an oil and gas platform and approached Iranian ships, the Iran's Islamic Revolutionary Guard Corps navy said.

This is the latest aggressive encounter involving the two navies. A similar incident, involving the US and Iran, took place in the region on Tuesday.

"With only a few days since a provocative move in the northern end of the Persian Gulf in which the US Navy ships fired warning shots at an Iranian vessel, the American warships have once again taken the same action in the middle of the Persian Gulf," CNN quoted Iran's Islamic Revolutionary Guard Corps statement as saying.

The US Navy ships were intercepted by IRGC missile boats near the Resalat gas-oil field, when they approached the Iranians and dispatched a helicopter at 4pm on Friday, according to the statement.

The American warships opened fire in what the IRGC described as "a provocative and unprofessional move." They then left the area, IRGC added, while the Iranians went on with their patrol.

On Tuesday, a US Navy ship fired warning shots at an armed Iranian patrol boat in the northern end of the Persian Gulf, according to two US defense officials.

It approached and came within 150 yards of the USS Thunderbolt, a US Navy patrol ship.

There had been 35 incidents of unsafe or unprofessional behavior by Iranian vessels in 2016.