“They were trying to get as much stuff as they could.

“They were all in black – all you could see was their eyes. It was out of the movies, it was mad scary.”

After around a minute, the raiders piled into a waiting Ford Mondeo, which was pointing towards the Netto on Salisbury Street. It was later found abandoned nearby.

There were no customers inside the shop during the raid.

A police spokesman said: “Pykes jewellers on Grange Road, Birkenhead, was attacked by three males wearing masks.

“They were initially reported to be armed with a firearm, but that has not been confirmed.

“They smashed the window at the front of the jewellers and stole a quantity of Breitling watches.

“They made off in a stolen Mondeo, which has been recovered and undergone a forensic examination.”

Pykes was last targeted by smash-and-grab burglars in June. The attack is also similar to a jewellery heist in Heswall at the end of November.

Then, three men wearing white boiler suits drilled through the front window of Hallmark, on Pensby Road. They then smashed the window with a sledge hammer and made off with up to £100,000 of jewels. Police are not yet linking the two raids.

The Birkenhead raid happened at around 4.15pm on Saturday afternoon. Police are appealing for witnesses to call 0151 777 2274, or Crimestoppers anonymously on 0800 555 111.