A 57-year-old Toronto man has been charged with first-degree murder after a man was struck and killed by a subway train at Bloor-Yonge station Monday morning.

The accused will appear in court on Tuesday morning.

UPDATE | Toronto police name accused in death of man pushed onto subway tracks

Earlier Monday, police said a man in his 40s had been arrested but not yet charged.

Police also said the victim, originally believed to be a man of Asian descent in his 20s, was in his 50s or 60s. The victim, who has not yet been identified, is described as having white hair and white eyebrows and was wearing blue running shoes, a white baseball cap and shorts at the time of his death.

"What I would like to request is that if anybody out there in the community knows somebody who might fit that description or who has a loved one who has not come home this evening or is unable to contact that loved one, please contact me," Det. Rob North said Monday evening.

There appears to have been no connection between the accused and the victim, police said.

Police said the victim was on the platform around 10:15 a.m. and "about to get on a train" when he appears to have been pushed into the path of an eastbound train on Line 2. Investigators don't believe there was any altercation between the two leading up to the incident.

The victim was taken to hospital, where he later died.

Police and transit officers arrested the suspect at the scene shortly afterward.

Witnesses asked to come forward

Seven or eight people are believed to have directly witnessed the incident and North urged them to get in touch with police.

"Video in the subway system is very clear video," he said. "Obviously we've seen something on there that causes us some concern."

Police said the man was arrested at the scene around 20 minutes after the initial 911 call, after walking away a short distance and then walking back.

North said investigators are not ruling out mental health as a possible factor in the incident, but are still investigating.

The push, he said, happened "very quickly."

TTC service resumes

The Toronto transit agency said service has resumed on its system after being disrupted for the investigation.

Trains on Line 2 had been bypassing Bloor-Yonge station, but have since returned to regular stops.

"While still under investigation, incidents of this nature are incredibly rare," the TTC said in a statement. The transit agency said it will review any measures that might reduce the chances of an incident like Monday's from happening again.

The TTC has provided surveillance video to police and has also arranged for counselling services to its employees, Ross said.

Line 1 had been closed between St. Clair and Union stations earlier Monday due to an injury on the tracks at College station.