GROZNY, April 30 (RIA Novosti) - Unidentified militants injured one serviceman in the center of Russia's North Caucasus republic of Chechnya in a grenade attack, a local police source said on Wednesday.

"Six shots were fired from an RG-6 portable grenade launcher at an interior troops post at around 10:00 p.m. Moscow time [18:00 GMT] on Tuesday. A contract soldier was injured, and has been given medical assistance," the spokesman said.

An investigation is underway.

Chechnya was devastated by two military campaigns, in 1994-1996 and 1999-2001, after which Moscow significantly scaled down its military presence in the republic. But random fighting and terrorist attacks still occur in the area, despite a widely publicized amnesty campaign announced by Russian authorities.