The “quick actions” of a female worker at a town centre jewellers targeted in a botched smash-and-grab raid helped foil the armed robbers, police have said.

An investigation was launched after four people on two mopeds failed in their bid to smash their way through the display window at Robert Gatward Jewellers in the Buttermarket at around 4.50pm on Monday.

Eyewitnesses described the “shocking” raid as a bungled smash-and-grab attempt, raising questions over whether the would-be burglars were targeting a new range of deluxe Rolex watches, worth more than £20,000, at the high-class jewellers.

It is understood the watches were delivered over the weekend. Police believe raiders used an axe or a jemmy type tool to gain access. No arrests have been made and the mopeds have not been recovered.

Staff at the store declined to comment, but a Suffolk Constabulary spokesman has described how one employee spotted the gang driving slowly on their mopeds towards the shop from the direction of Queens Street.

“Fearing they were about to be raided, the employee alerted her colleagues and security procedures were activated and the alarm was raised,” the spokesman added.

Two knives dropped by the offenders as they fled the scene on white and red mopeds, believed to be Vespas, were recovered by officers.

And Suffolk Constabulary Acting Detective Inspector Dan Connick, from Ipswich CID, hailed the actions taken by the staff member.

“This is obviously quite a distressing incident for the staff at the jewellers but thankfully, due to their quick actions, they were able to activate their security procedures and entry to the store was not gained,” he said.

“We have spoken to a number of witnesses from the scene and we are reviewing CCTV footage. However, we still need to speak to anyone who saw the mopeds and those riding them.” Call police on 101.