POLICE are seeking witnesses after a robbery on a Charlestown sporting oval in the early hours of Sunday.
A woman and five men were sitting on the field near the Pacific Highway about 12.40am when a man approached the group.
Armed with a knife, he threatened the group and stole their wallets.
No-one was injured.
He was last seen headed towards Lincoln Street.
Lake Macquarie police are investigating and wish to speak to a man who can help their inquiries.
He has been described as in his 20s, about 168cm tall and was wearing a grey hooded jumper and a grey or navy balaclava.
Anyone within information is urged to call Crime Stoppers on 1800 333 000.