WASHINGTON (Reuters) - A passenger at Detroit's airport was found with a concealed knife in his shoe and was arrested, the Transportation Security Administration (TSA) said.

TSA officers found the knife in the bottom lining of the man's shoe during checkpoint screening at Detroit Metropolitan Wayne County Airport on Sunday, the agency said in a statement.

Airport police confiscated the knife and arrested the man on a local charge, it said. Knives and most other sharp objects are barred from carry-on luggage.

TSA officers routinely turn up knives and other prohibited objects. A TSA blog said that from June 27 to July 2, the agency discovered 33 firearms - 25 of them loaded - a samurai sword, fireworks, a stun cane, stun guns, a hair brush dagger and inert grenades, among other items.

The arrest came a few days after the TSA announced it would tighten security amid concerns that al Qaeda-linked groups are plotting to blow up an airliner, U.S. officials said.

(Reporting by Ian Simpson; Editing by Bill Trott)

[Man with knife via Shutterstock]