A POST office has been forced to temporarily close after armed robbers burst in and repeatedly smashed a counter window with a sledgehammer.

The three men, who were also brandishing an axe and bat, tried to rob the post office in Plodder Lane, Farnworth, as terrified staff looked on.

Police are now hunting for the balaclava-clad men who fled empty handed in a black Mercedes car at 5pm on Thursday.

Nobody was hurt but a police spokesman said the shop's staff had been left "stressed and traumatised" by the incident.

None of the staff were available for comment.

Shocked business owners in the area have condemned the robbers as "cowardly" and say they are worried that they too may be targeted.

Rosie Smith, who runs a cafe a few doors down from the post office, said it had been a terrifying incident for the staff.

She said: "These robberies are happening all the time. It is not the first time it has happened there. They have just got to try and keep themselves safe. I am glad that they were not hurt that's the main thing.

"It is horrible to think that something like that could happen next door. You do worry as they might be carrying weapons and anything could happen. It is cowardly behaviour, it really is."

A sign on the door of the post office reads: "Due to an incident, this office is closed temporarily. For all post office and bank account holders, cash is available from out ATM machine in the side street. Sorry for the inconvenience."

It is not known when the post office will reopen.

Two police cars arrived immediately after the robbery and officers examined the scene for forensic evidence.

On July 17, police conducted a succession of search warrants in response to a spate of armed raids involving axes and machetes.

They arrested a 24-year-old man from Heaton on suspicion of robbing Aldi in Trinity Street on June 29, with a 28-year-old Salford man arrested on suspicion of the Asda robbery.

A police spokesman said it was too early to know if the latest robbery was linked to the previous incidents.

He said: "We were called to reports of an armed robbery at 5pm. Three men carrying weapons had demanded money, but fled empty-handed.

"We are appealing for any witnesses to come forward."

Anyone with information should call police on 101 or the independent charity Crimestoppers, anonymously, on 0800 555111.