Police are appealing for information following an assault near the tunnel in the Woodhouse Street area of Portadown.
It is reported that a 36-year-old man was assaulted at approximately 4.30pm last Thursday by two men armed with a hammer.
The man managed to run off but required medical treatment for his injuries which were not life-threatening.
A 31-year-old man was arrested in connection with the incident but was released on police bail pending further enquiries later that evening.
Constable Phil Orr said: “I would ask anyone who knows anything about this incident to contact Lurgan Police Station on the non-emergency number 101, quoting reference number 961 of 15/12/16.
“Or if someone would prefer to provide information without giving their details, they can contact the independent charity Crimestoppers and speak to them anonymously on 0800 555 111.”