The Fredericton Police are using a marine unit to check the St. John River for a man who has been missing for several days.

Michael John Lyons, 25, was reported missing by his family on Thursday. He was last seen by his father on Wednesday around 4 p.m. at the exhibition grounds on Saunders Street.

Michael John Lyons was last seen Wednesday.Michael John Lyons was last seen Wednesday. (Fredericton Police)

Det. Jeff Lingley of the Fredericton Police said his father said he was in good spirits.

On Thursday, searchers found Lyons' bookbag around the York Arena on the northside.

Saturday, the search spread to the St. John and Nashwaak Rivers.

"The marine unit section patrolled up and down the shores and along the Nashwaak River, just looking for some signs where he could possibly be," said Lingley.

The marine unit will be back on the water on Sunday, Lingley said. In the meantime, police are hoping tips will come in to help locate Lyons.

He's described as 5' 10" tall, 130 pounds, with short blond hair. At the time he went missing, he was thought to be wearing glasses, grey pants and a blue and white striped dress shirt.

The police are asking anyone with information to contact them.

The police said no foul play is suspected.