Shoppers and staff at the Rideau Centre were evacuated from the mall Friday afternoon after carbon monoxide was detected on the first floor.

Ottawa Fire Services received a call just after 12 p.m. after a carbon monoxide alarm went off in a store. Staff had already started to evacuate people from the mall. After firefighters arrived, they detected CO levels between 30 and 50 parts per million.

Ottawa fire told CBC News the smell was caused by exhaust from a forklift.

The Ottawa Fire hazardous materials unit, Ottawa police, paramedics and OC Transpo also assisted with the evacuation.

Crews ventilated the mall and gave the all clear at 1:36 p.m.