One man is dead and two others seriously injured after separate knife attacks in Melbourne on Thursday morning.

Police said a man died after he was found outside a block of flats in North Melbourne, while two men in their 20s were attacked by a group on a street in Noble Park.

Police said the victim of the North Melbourne stabbing died at the Royal Melbourne Hospital after being treated by paramedics at the scene.

Emergency crews were called to the entrance of the flats, on Courtney Street, about 4:45am.

Police said they have not yet worked out the circumstances of the stabbing and were doorknocking the area on Thursday.

Russell Mulry, who works nearby on Queensberry Street, said he was shocked to hear what had happened in an area he said was not usually violent.

“You get the few odd people walking around the streets as you do in every suburb and town, but I haven’t seen anything out of the ordinary,” he said.

“I park my car here most days and stuff, but I don’t think I’ll be doing that now that I know that someone has been stabbed a few metres from where I park my car.”

In Noble Park, two men in their 20s were stabbed after they were approached by a group of men.

“Investigators have been told the pair were walking in the vicinity of Corrigan Road and Green Street about 1am when they were approached by five to six men armed with a knife, who made demands for cash,” a police statement said.

“The men refused and an altercation occurred, with both sustaining stab wounds.

“The group then fled the scene with an amount of cash.”

Both of the men were found on the street and taken to hospital.

Ambulance Victoria said the men were now in a stable condition in the Alfred Hospital.