Anthony Di Monte says the two are in an intensive care unit with second-degree burns to their hands, legs and other areas.
Di Monte says the exercise involved using explosives to force an entry to a house.
After the explosion, other paramedics on the scene rushed to help the injured and transport them to hospital. Three other people — one paramedic and two Ottawa police officers — sustained minor injuries.
The chief says the two male paramedics are experienced members of a tactical team that routinely works with police.
Ottawa police Chief Charles Bordeleau told a news conference the incident is under investigation by the province's Special Investigations Unit.