Boston police have denied reports by some US media outlets that a suspect has been arrested over the marathon bombings, which killed three people and injured another 150.
CNN and the Boston Globe reported that an unidentified law enforcement official said an arrest had been made on the basis of a person caught on tape in two videos.
The Associated Press said an arrest in the case was "imminent".
But a Boston Police said there had been no arrests.
Three people were killed in Monday's attack
NBC and CBS also reported they were not aware of any arrests over the case.
Reports came hours after the FBI said it was examining images of a grey and orange bag pictured on the Boston Marathon route where the second bomb was detonated.
The images, taken by a member of the public, were submitted to NBC station WHDH and have been passed to the authorities for review.