The shooting of a man as he lay in his bed could have been a "warning" rather than an attempt on his life, police believe.

The 20-year-old was lying next to his wife when shotgun rounds smashed through the window of a caravan on Whinney Hill travellers site.

Two pellets ricocheted off the window and into the man's left hand. His wife, in her 20s, was unharmed but left shaken.

Detectives said a gang of men drove a car onto the Accrington site at 4.30am on Monday, fired the shots, then left. Following the incident police launched an attempted murder probe.

DCI Dean Holden said the shooting could be related to a dispute between two families of travellers.

He also said police were investigating whether the shots had been fired as a warning rather than an attempt to kill the people in the caravan.

He said: "We are confident the offenders are from outside the area. It was a targeted attack. In terms of wider risks there isn’t one. People aren’t shooting at other people’s houses. They have shot through the window of a caravan with a shotgun. It could have been more of a warning shot than attempted murder."

Parts of the site were sealed off on Monday as forensic officers searched the area for clues. Police are now scouring through CCTV footage and interviewing witnesses.

On Monday six people – a woman and five men – were arrested on suspicion of attempted murder. They have since been released without charge.

DI Claire Holbrook said: "This has been at the very least a serious attempt to intimidate the victims and this is undoubtedly an extremely serious offence that will be investigated robustly and thoroughly.

"All avenues will be investigated to ascertain the exact intentions of the offenders, whether that is attempted murder or any other offence."

"In an investigation of this magnitude it is not unusual to make many arrests to ascertain who is and who isn’t involved in such an offence."

Senior Investigating Officer, Detective Superintendent Andy Murphy is urging anyone with information to get in touch with police.

Police said firearms incidents in East Lancashire and the rest of the county were very rare.

Contact police on 101 or Crimestoppers anonymously on 0800 555111 or online at www.crimestoppers-uk.org.