Toronto police have charged four people with first-degree murder in connection with a fatal stabbing outside a North York highrise last month.

Two 18-year-olds and two teenagers who cannot be named under the Youth Criminal Justice Act were arrested during a series of raids Tuesday morning.

Allen Benn, 20, died after being stabbed in the chest April 2 outside a stairwell at 40 Turf Grassway, in the Jane and Finch area. He is the city's 12th homicide of the year.

Detectives believed as many as six men were behind the vicious attack.

Charged are Shaun Blake, Mackel Peterkin and two boys, all from Toronto.

The accused were to appear at the Finch Avenue courts on Tuesday.

Anyone with further information is asked to contact police at 416-808-7400, Crime Stoppers anonymously at 416-222-TIPS (8477), or online at www.222tips.com.