Extra officers will be on patrol in Norwich over the coming days as detectives continue to investigate the murder of a man at a city car park.

Norwich Evening News: Police have launched a murder inquiry after a man in his 40s was stabbed at Rose Lane car park. Picture: Dominic GilbertPolice have launched a murder inquiry after a man in his 40s was stabbed at Rose Lane car park. Picture: Dominic Gilbert (Image: Archant)

Police were called to the Rose Lane car park in the early hours of Saturday morning (June 23) following reports a man in his 40s had been stabbed.

The man was taken to the Norfolk and Norwich University Hospital for treatment, but died from his injuries.

A man in his 20s has since been arrested on suspicion of murder and remains in police custody.

Norfolk Police said a Home Office post mortem examination to establish the exact cause of death will take place in due course.

Norwich Evening News: Police have launched a murder inquiry after a man in his 40s was stabbed at Rose Lane car park. Picture: Dominic GilbertPolice have launched a murder inquiry after a man in his 40s was stabbed at Rose Lane car park. Picture: Dominic Gilbert (Image: Archant)

The victim is yet to be formally identified, police said.

A cordon remains around the scene and is expected to be there for several days while detectives continue enquiries.

Inspector Dan Cocks said: 'Detectives are in the early stages of their investigation and extra officers will be on patrol over the next few days to offer support and to reassure members of the public.

'Whilst local roads around Rose Lane have been reopened and are accessible to traffic, please be aware that if you are planning on going out into the city this evening that there will be an increased police presence in that area.'

Norwich Evening News: Police have launched a murder inquiry after a man in his 40s was stabbed at Rose Lane car park. Picture: Dominic GilbertPolice have launched a murder inquiry after a man in his 40s was stabbed at Rose Lane car park. Picture: Dominic Gilbert (Image: Archant)

Cordons were put in place along Rose Lane and Mountergate straddling the junction with Eastbourne Place.

A further cordon had been put in place at an alleyway off Boulton Street - further up Rose Lane towards Market Avenue.

It has now been reduced in size to cover a section of St John's Street between Mountergate and Rose Lane.

The barriers at Rose Lane car park have now been lifted so around 140 cars, which had been off limits, can be removed.

Norwich Evening News: The cordon in place at St Johns Street after a man was fatally stabbed at Rose Lane car park. Picture: Dominic GilbertThe cordon in place at St Johns Street after a man was fatally stabbed at Rose Lane car park. Picture: Dominic Gilbert (Image: Archant)

Witnesses have said a huge police presence descended on the area around midnight - with armed units deployed at Norwich railway station.

Hakan Kayahan, 57, was working at Best Kebab and Pizza on Prince Of Wales Road at the time.

'The train station was full of police,' he said. 'There was eight armed units up there and ambulances as well.

'All we heard is from a group of people in front of the shop who said someone had been stabbed.'

Norwich Evening News: The scene after the stabbing on Rose Lane on Friday night. Picture submittedThe scene after the stabbing on Rose Lane on Friday night. Picture submitted (Image: Archant)

65-year-old Gamini Tennakoon arrived at work at Mallie News on Prince of Wales Road around 5.30am.

'I came in first thing this morning to collect the papers and the first thing I saw was police cars,' he said.

'The last time something like this happened they closed off the same part when there was a hit and run.

'A homeless man came in to the shop and told us someone had been stabbed. It is very sad. We had only closed up shop at 11.30pm last night.

'When I came in to open up the shop there were police everywhere.'

Anyone with information should contact Norfolk Police immediately on 101.