TOKYO (AP) _ Two small, homemade rockets were fired into Tokyo's main international airport Monday, injuring one person.

A guard discovered a device in the parking lot of a hotel near the airport, and the object launched two of the projectiles before police were able to examine it, said police spokesman Hideki Kobayashi.

An airport employee was slightly injured by fragments of the projectiles, which landed near the cargo plane hangars. It was unclear what the rockets were made of.

Runways were closed for six minutes for inspection, but they were not damaged. The airport is located in Narita, 40 miles northeast of Tokyo.

Kobayashi said radical groups opposing the expansion of the airport were suspected of being responsible for the rockets. For decades, several left-wing groups have protested the airport, fearing it could be used for military purposes.