HILO, Hawaii (AP) — Operations at Hawaii’s Hilo International Airport were halted when security screeners spotted two items that looked like grenades in a bag belonging to a man from Japan.

Officers evacuated the terminal area Tuesday morning while a bomb squad determined the grenades were inert, according to a Hawaii Police Department statement. Airport operations resumed about an hour later.

Police spokesperson Denise Laitinen said in an email Wednesday that she’s looking into details about the grenades being inert.

Police arrested a 41-year-old man from Kanazawa, Japan, on suspicion of first-degree terroristic threatening. He was taken to an east Hawaii detention facility and then released pending investigation, police said.

The Transportation Security Administration prohibits replicas of explosives, including hand grenades, in checked or carry-on luggage.