Emergency crews are searching the Ottawa River near the interprovincial bridge east of Pembroke for a missing paddler.
Ontario Provincial Police (OPP) said on social media Wednesday two paddlers were in a tandem kayak that capsized the night before.
Police said a 34-year-old man was rescued by a citizen, but a 30-year-old woman remains missing.
Ontario and Quebec provincial police, the Pembroke Fire Department and Renfrew County paramedics are among the agencies involved in the search, OPP said.
The Des Allumettes Bridge is about six kilometres east of downtown Pembroke and 110 kilometres northwest of downtown Ottawa.