A man was stabbed in the stomach and another suffered serious head injuries after a gang fight on Sunday evening.
The pair, aged 27 and 33, were assaulted in Monk's Park, Wembley, next to the eastbound North Circular Road, by a group of around 20 black men, at 7.30pm
Both were taken to hospital where they remain in a stable, non-life-threatening condition.
Police are unclear whether a verbal exchange took place before the fight and do not know what direction the men came from, or headed to after the incident.
Anyone with information should call Wembley CID on 020 8733 3159 or Crimestoppers anonymously on 0800 555 111.