Police and the media are being accused of playing down a bomb alert in a Preston shopping centre because the man officers want to trace appears to be white.

Lancashire Constabulary said the “crude incendiary device” ignited in the men’s toilets at the Fishergate Shopping Centre on Thursday morning but did not injure anyone.

The improvised package, reportedly made using an asthma inhaler, firelighter, matches and toilet paper, was found by a shopper who put out the flames and is currently being analysed.

Police released CCTV footage of a man they wanted to speak to, which shows him walking up an escalator at the nearby St George’s Shopping Centre around 40 minutes before the fire started, carrying a plastic bag.

Detective Chief Inspector Jill Johnston, from Preston Police, said: “We are treating this as a criminal investigation and while the motivation for this incident remains unclear at this stage, we believe this device has been left there deliberately and did have the potential to cause serious injury if it had exploded.”

People commenting on social media noted the lack of references to terrorism in official statements and accused some media outlets of not giving enough prominence to the story, claiming that the response would have been different if the man in CCTV footage did not appear to be white.

Here are some of their comments:

Lancashire Constabulary could not be reached for a comment.

Bomb disposal officers were called to the Fishergate centre after it was evacuated as a precaution and shut down for searches. It was due to re-open today.