Three men arrested by police investigating two robberies at Mansfield Woodhouse post offices have been released.
Officers arrested the men in connection with robberies at post offices on Brown Avenue and Station Street.
The men, two aged 27 and a 31-year-old, were arrested on suspicion of conspiracy to commit robbery, but a spokesman for Nottinghamshire Police said they have since been released pending further inquiries.
And police have now issued a fresh appeal for witnesses as they continue to investigate the robberies.
Officers were called to reports of an attempted robbery on Brown Avenue on Monday, April 24, just before 11.30am, and a robbery on Station Street on Saturday, April 22, at 11.50am.
Detectives believe the incidents are linked and that a black Peugeot 207S stolen in the local area was used in both incidents.
Enquiries are ongoing and officers have been out on patrol in the area to provide reassurance to the local community.
Detective Sergeant Ricci Skelton, of Nottinghamshire Police, said: “Inquiries made so far show that there were a number of members of the public present at both scenes who were potentially photographing or recording the incidents.
“We would like these to come forward.”
Police are appealing for anyone with information about either of the incidents to call Nottinghamshire Police on 101, quoting incident numbers 259 of Monday, April 24, and and 306 of Saturday, April 22, 2017, or Crimestoppers anonymously on 0800 555 111.
In the Station Street robbery, two men wearing dark clothing and balaclavas entered the property. They threatened staff and attacked tills before leaving with a quantity of cash.
They made off in the Peugeot 207S.
In the attempted robbert, two men wearing balaclavas, dark clothing and gloves entered the property just before 11.30am.
One of the males reportedly ran into the post office armed with a knife and tried to grab the till from the kiosk.
It is understood he waved the knife at a staff member before running out of the Post Office.
A second man is then reported to have entered the store, armed with a hammer, and threatened post office user David Clough, who tried to intervene and stop him leaving.
Mr Clough, aged 62, said: “I knelt on my mobility scooter so I could grab the guy who was about to come out.
“But then the driver came out and threatened me with a hammer.
“He said if I didn’t get out of the way, there was going to be trouble, but I didn’t move.
No-one was injured. Both males fled empty-handed and made off in a vehicle at speed.