The RCMP says a fast current is making it harder to search for a teen swimmer who went missing from the South Saskatchewan River near Saskatoon.

The 17-year-old boy went missing Sunday evening just before 9 p.m. CST from the beach at the Fred Heal canoe launch about 12 kilometres south of the city.

Overnight searches were conducted by RCMP, Saskatoon city police and STARS Air Ambulance, said the RCMP's commander of the Saskatoon detachment, Greg Abbott. The search is complicated by the rapid current and the large area, he added.

RCMP missing teen Saskatoon

The RCMP is searching the South Saskatchewan River near Saskatoon for a missing teen swimmer. (Jason Warick/CBC)

On Monday afternoon, relatives of the missing teen sat on lawn chairs and paced around the beach where the search continues. On the shore and in the water, dozens of volunteers, police and firefighters looked for the teenager.

The family declined to speak with media, but Abbott said they are grateful for all the help.

"As you can well imagine, it's extremely stressful. That's why we're doing all we can," Abbott told reporters at the boat launch site near the Beaver Creek Conservation Area.

RCMP said they would not be releasing the teenager's name.