Ontario’s police watchdog agency says it is investigating two separate incidents during this weekend’s clear-out of anti-mandate protesters in Ottawa; one where a woman was allegedly injured by a police officer on horseback and another where hard anti-riot projectiles were fired into a crowd.

The Special Investigations Unit (SIU) says that 5:14 p.m. on on Friday, a Toronto police officer on horseback made contact with a 49-year-old woman at Rideau Street and Mackenzie Avenue, north of the Senate of Canada building and east of the Chateau Laurier Hotel.

The SIU says the woman suffered a serious injury in the encounter.

The next day at 7:18 p.m., the SIU said that a group of Vancouver police officers operating near Bank and Sparks streets fired Anti-Riot Weapon Enfield (ARWEN) projectile launchers at people gathered in the vicinity.

The ARWEN fires a 37 millimetre polymer baton-shaped round at up to 242 feet per second.

Investigators say they have so far not located anyone injured by the projectiles, but are asking anyone who was struck by them to contact the SIU.

"We are aware that the Special Investigations Unit has invoked its mandate with respect to two incidents. One relates to an interaction involving a police force. The other relates to the discharge of the ARWEN," Ottawa police interim Chief Steve Bell said at a news conference on Sunday. "Any questions relating to these two incidents must be directed to the Special Investigations Unit."

Police tactics at the operation have been the subject of intense scrutiny, with a foreign media personality falsely claiming someone was trampled to death by a police horse on Friday.

The SIU is called in to probe any incident involving a police officer operating in Ontario and a member of the public where there is a death, serious injury, allegation of sexual assault or the discharge of a firearm at an individual.