Hawaii island police have arrested a 41-year-old man from Japan after two items resembling grenades were found in his carry-on bag at Hilo International Airport.

Police said they were called to the airport at about 5:44 a.m. by Transportation Security Administration agents after the grenades were detected during routine X-ray screening.

The Hilo airport experienced a brief halt in operations as police investigated, and then arrested Akito Fukushima, 41, of Kanazawa, Japan, on suspicion of first-degree terroristic threatening. Police evacuated the terminal area out of an abundance of caution while the department’s bomb squad investigated, and determined the grenades to be inert.

The Hilo airport resumed operations at 6:50 a.m.

Fukushima was taken to HPD’s East Hawaii Detention Facility, where he remains in custody as the investigation continues.

“Police remind the public that replicas of explosives, such as hand grenades, are prohibited in checked and carry-on baggage,” said HPD in a news release. “TSA officers also have the discretion to prohibit any item through the screening checkpoint if they believe it poses a security threat.”

The TSA issued a statement: “TSA reminds everyone that grenades of any type – including replicas – are not allowed in either checked or carry-on luggage. When a traveler brings any type of grenade to the airport, it causes operations to shut down and delays travelers. Please be aware of the contents of your luggage prior to coming to the airport to avoid this type of situation from occurring.”