Armed thieves stole up to £40,000 in a lightning-fast raid.

The two thieves burst into a post office in Barmulloch, threatened a worker with a knife and demanded money.

Onlookers described the robbery as a "minute of mayhem" as the gang were in an out of the shop unit in a matter of seconds, clutching the five-figure sum of cash.

Police said the 27-year-old male member of staff was not injured, but has been left "badly shaken" by his ordeal.

The suspects targeted the post office in Quarrywood Avenue, early last Friday morning, an hour before opening time.

A police source said it appeared to be "extremely well planned".

It happened at around 7.55am and the two raiders were last seen making off on foot.

One source said: "It was all over very quickly.

"They were in and out in a minute of mayhem."

Police are now reviewing CCTV footage from the post office and surrounding area in a bid to identify the two raiders.

Police believe local residents may have seen something of significance.

Witnesses have been asked to contact robbery unit detectives with any information.

Detective Sergeant Raymond Hunter, who is leading the probe, has urged any witnesses who saw suspicious activity near the post office, or who saw the crooks escape, to come forward.

He said: "We have been are carrying out door-to-door inquiries and are in the process of collecting CCTV images from the surrounding area.

"There are a number of other shops in this area and people may have seen the two men prior to or after the incident.

"I am therefore appealing to anyone who was in the area or any local residents to contact us. Any information you have could assist our inquiry."

Both suspects are white males.

One of them is believed to be between 35 and 40-years-old, with short brown hair.

At the time of the raid, he was wearing a black jumper.

Meanwhile, investigations are continuing into a failed robbery attempt at a Glasgow bookies.

An armed man entered the Ladbrokes shop in Union Street in the city centre at around 10am.

He threatened a worker and demanded money.

However, he fled empty handed. It is understood a member of staff managed to raise the alarm and stop the raider from getting any cash.

The branch is near a busy bus stop and police have asked any witnesses to come forward.

As previously revealed by the Evening Times, round-the-clock dedicated crime units have seen the robbery rate in Glasgow in the past five years drop by 67 per cent.

Detective Superintendent Stevie Grant believes having a unit which focuses primarily on robberies - and the repeat offenders behind crimes - is the key to driving down the number of incidents.

Anyone with any information is asked to contact the robbery unit at Pollok Police Office on 101.