A Hawaii airport was briefly evacuated after a Japanese man was found with two inert grenades in his hand luggage, police said following his arrest.

Officers cleared the terminal on Tuesday while a bomb squad moved in to investigate the suspicious items, which were picked up on an X-ray machine.

"The Hilo International Airport experienced a brief halt in operations" for little over an hour, Hawaii police said in a statement.

The bomb squad "determined the items to be inert grenades," police reported, meaning they were not dangerous.

Akito Fukushima, 41, of Kanazawa, Ishikawa Prefecture, was arrested on a "terroristic threatening" charge and remains in custody, the police said.

"Police remind the public that replicas of explosives, such as hand grenades, are prohibited in checked and carry-on baggage," it said.