A 14-year-old girl from Preston has been arrested in connection with a video appearing to show youths burning a homeless man's sleeping bag.
The teenager was arrested by police at Lancashire Constabulary on suspicion of a public order offence.
Footage shows a group of youths taunting the man with a knife, before his sleeping bag is set on fire.
Police are now trying to locate the homeless man, who was sleeping in the Market Car Park when he was approached by the youths on Saturday September 8.
Inspector Helen Dixon, of Lancashire Constabulary’s South Division, said: “This is an extremely unpleasant incident and we are working with outreach services in the city to find this man and address any safeguarding concerns.
“We are also trying to identify the young people in the video so we can take appropriate action.”
Anyone with information is asked to call 101 quoting log 751 of September 26.