World Bulletin / News Desk
Dogan News Agency said police had detained a man, believed to be mentally unstable, for questioning. A police official said he was not able to immediately comment.
A U.S. diplomat told Reuters the consulate had taken precautionary measures following a security alert.
Istanbul has been on high security alert since January, when a suicide bomber blew herself up at a police station in the historic Sultanahmet district, killing one officer and wounding another.