Two people have been detained and two other remain outstanding after Toronto police responded to a reports of a person with a gun inside a Scarborough high school.

At 1 p.m. today, Toronto police were called to David and Mary Thomson Collegiate Institute, which is  north of Lawrence Avenue East and east of Midland Avenue.

The east-end high school, along with the neighbouring Donwood Junior Public School were subsequently placed in lockdown.

A short time later, four other nearby schools, Lloyd Roberts Junior Public School, Charles Gordon Senior Public School, Edgewood Public School, and Northern College, were placed under a hold and secure order as a precaution.

Students and staff at all of the affected schools have since been let out.

No injuries have been reported. 

Speaking with the media late Thursday afternoon outside David and Mary Thomson Collegiate, Acting Insp. Duty Insp. Jason Albanese said police provided an "extremely robust response to this pressing matter."

He said officers did a systemic search of the school where they looked for any persons of interest or property related to this incident.

"I can tell you that we have located one replica firearm inside the school that we believe is connected to this and we have two people that we have detained at the moment," he said, adding he cannot say much more as the investigation is still "very active."

Two other people wanted in connection with this incident are outstanding, he added.

Albanese said the two individuals in custody are "affiliated to the school in some way" and that "multiple people" are involved in this incident.

Toronto police also closed a number of roads in the area of Brockley Drive and Treewood Street as they investigated. 

This latest situation is one of number of incidents that have occurred at Toronto school in recently weeks. 

On Oct. 31, an 18-year-old man was killed following a shooting outside Scarborough's Woburn Collegiate.

Two weeks later on Nov. 14, a stabbing inside a Scarborough's Birchmount Park Collegiate Institute left a 17-year-old student with critical injuries.

A day after that incident, Toronto Mayor John Tory said he would meet with various stakeholders to discuss school violence. That meeting was held on Monday morning.

Toronto police said they're also taking these "ongoing situations" "very seriously" and are working "very diligently" to solve the problem.

"So obviously, we have had a significant number of high profile incidents at high schools over the last few weeks, and several months. This is a very concerning matter for the Toronto Police Service as well as the Toronto District School Board," Albanese said. "Administrators are here, the police and the administrators behind the scenes are working diligently to you know, come up with strategies to prevent this ongoing, these ongoing situations from happening."