Manila: A Filipino-American man was barred from boarding his flight back to the United States on Thursday after airport baggage inspectors found a hand grenade and a knife inside his backpack.

Cipriano S. De Guzman was checking in his baggage at the Ninoy Aquino International Airport at for his 10.35am China Airlines flight for Taipei, Taiwan when x-ray technician Nolasco Abanco saw a suspicious object in his hand luggage.

Inspectors searched De Guzman’s bags and found a Mark 2 fragmentation grenade and a kitchen knife. Both items are banned aboard commercial flights.

In television interviews, De Guzman denied that he owned the items.

The naturalised American was planning to return to Florida via a Taipei connecting flight when the incident took place.

According to Col. Ricardo Layug of the police Aviation Security Group, investigations are on going into the matter.

He said De Guzman would likely be charged with “illegal possession of an explosive device and illegal possession of a sharp object.”

“Definitely De Guzman cannot leave the country,” Layug said in television reports.

The Aviation Security Group will turn de Guzman over to the Pasay City Fiscal Office for inquest procedures.

A background check is expected to be conducted on De Guzman on whether he has links to any terror groups or what was his possible motive.

According to Manila International Airport Authority General Manager Jose Angel Honrado, such cases show the importance of security screenings at NAIA.

Passengers have to go through security screenings at least twice in the terminals to make sure that prohibited items are seized before boarding.

“Passenger safety is always management’s priority. As such, passengers can be assured that security personnel are always vigilant while security equipment functioning,” Honrado added.