One person was shot dead and three were seriously wounded in downtown Ottawa on Wednesday, about a kilometre (0.6 miles) from parliament, police said.
Police in the Canadian capital responded to reports of multiple gun shots at about 7:30am ET and three people were rushed to the hospital, a statement said.
Police were seeking a suspect, it said. No further details were provided.
Local media cited police Inspector Francois D'Aoust saying it appeared to be a targeted shooting.
In 2014, a gunman attacked parliament and a soldier was fatally shot at a nearby war memorial. The attacker was shot dead by parliament security personnel, and the shooting was later classified as a terrorist attack.