The pictures were featured on national television during a reconstruction of the raids on BBC1’s Crimewatch programme.

Photos of the injuries caused to a mother and her 15-year-old son by the machete wielding robbers, were also shown.

The three men, who were also armed with a baseball bat type weapon, terrorized the occupants of the two houses in Wollerton, near Market Drayton just before 9am on April 5.

In the one property, Mrs Kathryn Burton received a cut to her forehead which needed gluing and her son William suffered a deep cut to his right hand while protecting his mother. He underwent surgery to the wound.

At the neighbouring address, Mrs Victoria Ratheram, who is eight months pregnant, was manhandled and tied to a chair.

Detective Chief Inspector Alan Edwards, head of Shropshire CID, said: “This was a violent and terrifying experience for the victims at the two homes. I am hoping The Crimeswatch reconstruction will persuade people to come forward with information.

“We are very anxious to identify and trace these men. They confronted vulnerable people in their own homes inflicting nasty injuries to a young boy and his mother as well as assaulting a pregnant woman. They were cowardly crimes.”

Both properties were ransacked before the gang fled with a small amount of stolen property in a black Land Rover Discovery taken from one of the homes. The vehicle was found within half an hour with its engine still running on the outskirts of the village.

Police believe the men then drove off in a silver coloured saloon car parked up in a nearby lay-by.

DCI Edwards said: “We are still investigating the motive for the attacks but at this stage, we do not think they were random.”

He revealed the men spoke with what appeared to be a Merseyside accent. “It’s quite likely they come from outside Shropshire and we are liaising with other police forces, including North Wales, Merseyside, Staffordshire and West Midlands.

“I am anxious to hear from anyone who spotted three or four men, possibly wearing hats, acting suspiciously in a silver car either the day before the attacks or during the early hours of Thursday, April 5 when their getaway vehicle may have been parked up on the approach to Wollerton.

“I am also appealing to members of the criminal fraternity to help as I believe they will not condone this kind of violence against women and children.”

Anyone with information for the police investigation team should contact Shrewsbury on 0300 333 3000. Information can also be given to the anonymous Crimestoppers charity by calling 0800 555 111 for which a reward may be paid.

All three men are described as white and around 5ft 10 inches tall. Two are thought to be about 40 years old and the third in his mid to late twenties.

The younger man was wearing a black woollen knitted beanie type hat pulled own over his eyebrows. He appeared to have short, light brown hair.