Three people arrested Wednesday in a series of pre-dawn raids have been charged with conspiracy to murder a member of the judicial system, Toronto police say.

Chief Bill Blair said the suspects rounded up are associated with a violent gang known as MS-13.

Blair would not elaborate on the conspiracy charges at a press conference on Thursday, but said the gang has a "propensity to use violence particularly against participants of the criminal justice system and in an attempt to intimidate witnesses and communities."

Staff Insp. Greg Getty said the alleged murder target could have been a police officer, court officer, member of the bar or member of the bench.

"The investigation involved someone within that process," Getty said. "This is still an ongoing investigation. And for the safety of the individuals involved as well as the public, we can not disclose anything at this time."

The raids at 22 locations came after a five-month investigation with Toronto police, members of their guns and gangs task force and Halton police. Officers seized a significant amount of cocaine, weapons, contraband material and $40,000 in cash related to the proceeds of crime.

Twenty-one people were taken into custody and 17 people have been charged, Getty said. Police laid 63 charges that included weapons offences and trafficking narcotics.

Court documents show some suspects shot at two Toronto officers during a west-end shooting last July, CTV Toronto's Austin Delaney reported.

There were more than 30 bullets fired in the exchange, which followed a store robbery and car chase near Jane Street and Black Creek Drive.

Blair said members of MS-13 often come to the United States and Canada as refugees from Central America. He said the gang is prevalent in North American cities as well as Central and South America.

"Their threat remains a significant one in Canada as it has emerged in the U.S. and Central America, so we will remain vigilant in assuring that this particular gang remain monitored and their activities curtailed," he said.

The chief also said he's confident the raids and subsequent arrests have put a dent into the gang's activities.

"We're confident with the conclusion of this investigation that we have identified the individuals who are responsible for establishing the MS-13 clique in Toronto," he said. "We believe with the arrest we have effectively ended the activities of this gang."

Blair said Toronto police are in contact with police forces across North America. He said traces of the gang were noticed back in the 1990s, but it wasn't until the past year that officers noticed the gang had stepped up their activities in the city.

Click here for a list of the names and charges in the investigation.