A gunman disguised as a police officer went on a 12-hour rampage in the Canadian province of Nova Scotia, shooting people in their homes, setting fires and killing at least 18 people, including a policewoman, in the deadliest mass shooting in the country’s history.

Officials said the suspect, identified as 51-year-old Gabriel Wortman, was also among the dead in the weekend attack. Police did not provide a motive for the killings.

Canadian Prime Minister Justin Trudeau said the gunman killed at least 18.