A man is in hospital with serious injuries after being stabbed in Whitehawk this afternoon.
There is currently a large police presence around Whitehawk Crescent, which police said was likely to remain for the time being.
The attack is believed to have happened near the Manor stairs.
A police spokeswoman said: “At around 12.45pm on Friday (14 July) police responded to a report of a man having been assaulted in Whitehawk Close in Brighton.
“He was taken to hospital with serious injuries, believed to have been caused by a bladed weapon.
“An urgent investigation is under way to establish the full circumstances of the situation and locate any suspects.
“The public can expect to see an increased police presence in the area at this time.
“Anyone with information is asked to contact Sussex Police either online or by calling 101, quoting serial 675 of 14/07.”