Niagara Regional Police confirm the bank robbery in downtown St. Catharines and the incident at Regional Headquarters are connected.
Police were called to the Bank of Montreal on King Street at 4:50 p.m this afternoon following reports of an armed robbery.
The suspects fled the scene and a brief pursuit followed which was ended out of concern for public safety.
The vehicle was then located east bound on Decew, and another police pursuit followed.
The suspect vehicle left the road in the area of 406 SB and St. David's Road.
The suspects then fled on foot.
It's believed at least one of the suspects could have entered Regional Headquarters looking to evade police.
At this time three men are in custody with one suspect is still out standing.
There is a large police presence in the area with emergency task unit as well as K9 members.