Police have released CCTV images of two girls who threatened to set a dog on passengers at Balham train station.

British Transport Police PC Rachel Smith said two sisters aged 29 and 25 were standing on platform four on January 6 when they saw the pair with a brown Staffordshire terrier.

"The sisters moved away, as one was scared of the dog, but the two other girls followed and began threatening to set the dog, believed to be a Staffordshire cross, on to the girls," PC Smith said.

"The two girls also threatened to throw the sisters onto the railway tracks.

"Once the train arrived the two girls boarded the same carriage as the sisters and approached the sisters and threatened them again.

"The sisters got off the train at Clapham Junction and were followed by the girls until one of the sisters informed them that she had called police.

"This sort of intimidating behaviour is not acceptable and we appeal to the public to help us in our investigation to ensure that we can identify those responsible and prevent further instances from occurring."

The two girls are described as about 15 years old and 1.65m tall.

The first was white, with a medium build and blonde shoulder-length hair, wearing a black jacket, dark-coloured jeans and trainers.

The second girl was black, heavily built, wearing a light-coloured jacket and blue jeans.

Anyone with information about the wanted pair should phone the BTP on 0800 405 040 or the Witness Appeal Line on 020 7391 5275.