The province's Special Investigation Unit is probing its second police chase in as many days after two shooting suspects were injured in an early-morning pursuit.

The high-speed chase began around 2 a.m. on Wednesday after police responded to a shooting near Parliament and Wellesley Streets.

The suspects fled north to Highway 401 and continued east where they lost control of their vehicle and crashed into a guardrail near Morningside Avenue and Ellesmere Road.

One suspect was arrested at the scene of the crash after a brief standoff with police.

"Seven officers surrounded the car and they ordered this man to get out. There was some type of confrontation between the officers and this man and shots were fired by police," SIU spokesperson Rose Bliss said Wednesday.

"The ETF team was then called and they arrived. After a series of negotiations and trying to get the man out of the car, they physically removed him from the vehicle and it was then that they noticed he was suffering from a serious injury in his head."

A second man was apprehended in a nearby ravine following a pursuit on foot. Authorities retrieved a firearm inside one of the vehicles.

Both men were taken to Sunnybrook Health Sciences Centre with serious injuries. Bliss said it wasn't clear if the men's injuries were inflicted by police.

While police pursued the suspects, the shooting victim was transported to hospital with a reported shotgun wound to the chest.

The intersection of Morningside Avenue and Ellesmere Road remained closed for several hours as police and SIU officials investigated the accident.

The chase comes a day after a 17-year-old Toronto boy was killed in a crash after being pursued by officers in the city's east end.

After running the licence plates on Shilton Lutchman's vehicle, police believed the car to be stolen. Lutchman's father told CTV News on Tuesday that the car was legally purchased.

The SIU, a civilian agency, investigates incidents involving police and civilians that have resulted in serious injury, sexual assault or death.