PEMBROKE, ONT. -- Upper Ottawa Valley OPP are investigating after a man showed up at hospital with stab wounds early Sunday morning.

A 21-year-old man was brought to the hospital around 4 a.m. Sunday with what police called serious but non-life threatening injuries.

OPP said the man wasn't forthcoming with information for responding officers, but police believe the 'serious assault' may have happened outside a Pembroke duplex Sunday morning. Police said it's not believed to be a random act and there is no known threat to public safety. 

Anyone with information is asked to contact Upper Ottawa Valley OPP at 613-732-3332 or 1-888-310-1122. Anonymous tips can also be left with Crime Stoppers Pembroke/Renfrew County at 1-800-222- 8477 (TIPS) or at