London police are investigating after a woman was sexually assaulted in a London park.

The assault occurred at McMahen Park near Adelaide St. North and Pall Mall Street around 1:30 a.m. Sunday.

The woman was in the park when she was approached from behind and sexually assaulted by an unknown man.

He is described as Caucasian wearing a dark colour long sleeve shirt.

The woman sustained minor injuries in the attack.

Anyone with information is asked to call police or crime stoppers.