Police tactical units converged on 25 locations throughout the GTA this morning, arresting 18 people allegedly connected to multiple "organized crime cells."

RCMP spokeswoman Cpl. Penny Herman said the arrests are related to the "importation of drugs," "firearms trafficking" and "extreme violence and extortion."

At least two of the arrests were made in Etobicoke. Officers with the Combined Forces Special Enforcement Unit moved into buildings at 205 and 215 Sherway Gardens Road around 5:30 a.m. ET and arrested two adult males at those locations.

RCMP and officers from forces in Toronto, York Region and Guelph took part in the operation, which followed a two-year investigation.

A police officer at the scene told CBC News the warrants were issued by the RCMP.

"The RCMP has dismantled several organized crime cells," Penny said.

RCMP will hold a press conference at 11 a.m. ET Wednesday to provide an update on the raids and arrests, according to a press release distributed Tuesday morning.