Police officers were left "confused" by a bird when it convincingly mimicked the sound of the sirens on their cars.

Thames Valley Police said staff initially thought their vehicles had developed a fault after hearing the noise at a roads policing base in Bicester.

A video filmed at the site in Oxfordshire and posted on social media shows the bird chirping in a tree - before then replicating the sound of a two-tone siren.

The force said that the copycat call was "100% real and not a late April Fools joke" and added that officers were left "a little confused".