(CNN) Five people were injured Friday in a stabbing at a shopping mall in Manchester, northwest England, and a man is being detained under the UK's Mental Health Act, police said.

The incident took place at the Arndale Centre at around 11:15 a.m. local time (6:15 a.m. ET), where a man who was carrying a "large knife" began "lunging and attacking people," Assistant Chief Constable Russ Jackson of Greater Manchester Police said.

Jackson said while the injuries are "nasty," none of them are life-threatening.

He said police did not know the motivation behind the attack, adding that "it appears random, and it is brutal."

Following the attack, a man originally was arrested on suspicion, preparation and instigation of an act of terrorism. He is believed to have acted alone.

Read More