Army bomb experts carried out a controlled explosion after a smoke grenade was found by a passer-by in a Bradford alleyway.

Police were called yesterday after the cannister, about 5ins long and covered in rust and dents, was found behind a solicitors office in Sunbridge Road.

Officers taped off the alleyway and called in bomb disposal experts from Catterick who removed the device and exploded it on wasteland off Ingeleby Road, Bradford.

A police spokesman said the explosion was no more than a “pop” but offiers would still be interested to hear from anyone who knew how the smoke greande had got there.

The spokesman said: “It was all rusty and covered in dents. The clip keeping it secure was off and lying nearby when it was found. Anyone who knows how it got there should call us.”

The non-emergency number to ring with informtion is 101.