"The US Military Academy is fully committed to developing leaders of character who embody the Army values," West Point Superintendent, Lieutenant General Darryl Williams, said in a statement.

"I have appointed an investigating officer according to Army regulation 15-6, to conduct an administrative investigation into the facts, circumstances and intent of the cadets in question," he said.

Before the game Saturday, which was attended by President Donald Trump, at least two West Point cadets and a US Naval Academy midshipman were seen holding out their hands in an inverted "OK" gesture that has become popular with white supremacist groups.

The military academy students made the hand gestures conspicuously as they stood behind an ESPN commentator as he spoke on live television.

Earlier a spokeswoman for the naval academy in Annapolis, Maryland told US media they were also looking into the incident.

Last year the US Coast Guard reprimanded an officer who flashed the same hand sign during a television broadcast.

Earlier this year West Point removed a slogan from its football team spirit flag because it had also become associated with racist and hate groups.

The flag featured a skull and crossbones and the letters "GFBD" which stood for "God Forgives, Brothers Don't."

The motto is used by, among others, the violent, all-white Aryan Brotherhood prison gang.

For decades the all-OK sign -- thumb and index finger in a circle and three other fingers extended upward -- has been a near-universal positive gesture.

The Anti-Defamation League says that the OK hand sign -- especially when displayed inverted, below the waist -- has become popular among some white supremacists in recent years, and is also used by conservatives simply to provoke liberals.

"Use of the 'OK' gesture has spread beyond the far right and can now also be found within the broad community of mainstream Donald Trump supporters -- some of whom seem to have no idea of its origins," the groups says.

Brenton Tarrant, the racist who murdered 51 people in attacks on two mosques in Christchurch, New Zealand on March 15, 2019, flashed the same hand signal -- an inverted "OK" below the waist" -- when he first appeared in court after his arrest.