U.S. officials in Turkey have banned U.S. military personnel from commercial areas outside an air base in southern Turkey, after an unexploded bomb was found near the entrance to the base.

Turkish news reports say authorities discovered the five-kilogram bomb late Tuesday outside a discotheque adjacent to the Incirlik air base in south-central Turkey. The air base was a staging area for U.S. forces in the 1991 Gulf war, and is currently used to supply U.S. forces in nearby Iraq.

The Anatolia news agency says a man and woman suspected of planting the bomb were seen with two bags in their possession, raising fears of a second bomb.

U.S. Secretary of State Condoleezza Rice visits Turkey this weekend.

Some information for this report provided by AP.