At least 12 people were injured, one of them seriously, in a grenade explosion inside a cinema hall in upper Assam's Tinsukia district on Wednesday afternoon, police said.

The blast took place in Paradise cinema hall in the heart of Tinsukia town just as the audience were entering for the matinee show at 1300 IST.

Most of the wounded received injuries in their legs.

One person, injured seriously in the blast, was shifted to the Assam Medical College Hospital in neighbouring Dibrugarh district.

The area around the hall has been cordoned off.