At least one person is dead after an explosion on Istanbul's popular pedestrian thoroughfare, Istiklal Avenue, according to the local governor, published videos and Turkish media.
The cause of the explosion in the Turkish capital on Sunday afternoon local time remains unclear but footage showed ambulances, fire trucks and police at the scene.
Istanbul's governor Ali Yerlikaya said in a tweet there were "casualties and injuries"
He said developments "will be shared with the public".
The nearby Kasimpasa police station said all crews were at the scene but gave no further details.
Social media users said shops were closed and the avenue shut down.
More to come.