A Melbourne shopping centre has been sent into lockdown, with shoppers and staff evacuated after an alleged knife fight involving 10 people.

Two men have been arrested after the incident at Northland Shopping Centre in Preston at 2.30pm, Victoria Police said.

A teenager has also been rushed to hospital with serious injuries, according to Ambulance Victoria.

“The centre was locked down as the incident took place and remains closed while police investigate,” Victoria Police said.

Footage shows shops with the shutters down as sirens sound.

One woman rang 3AW to report said she had been forced to shelter inside a shop with the lights off, before being told to “evacuate” the building.

“There were people screaming outside, people running,” Lina told 3AW.

“There was a lot of people running here and there going into stores.”

“We knew nothing, we saw a lot of frightened people.”

Other mobile videos show crowds of people leaving via stairwells, and a helicopter overhead.

It is understood people have now been let out of the centre.

Police say they believe the gangs knew each other, and are appealing for witnesses.