Police say five suspicious envelopes delivered to Saskatoon businesses on Tuesday contained baking soda and talcum powder.

A contamination scare put parts of the city into lockdown, with suspicious envelopes delivered to five businesses.

Police say they have three people in custody -- one male and two females -- who are facing five charges of public mischief, mischief and utter threats to cause bodily harm.

Police do not believe there is anyone else involved.

Speaking to reporters at about 4:30 p.m. CST, Saskatoon Fire Department Fire Chief Morgan Hackl said initial test results for the first two envelopes showed the powder was sodium bicarbonate, or baking soda. The remaining three envelopes were later found to contain baking soda in two packages, while one had talcum powder.

The packages will be sent to Winnipeg for final testing.

"We have to approach it with diligence, we have to go through all the proper steps," Hackl said in a press release on Tuesday evening. "Whether it's a malicious call or not, we can't take that into account – we have to take the due course and take it seriously."

Two hotels, a restaurant and an office tower were among the affected businesses.

Police arrived at the restaurant on 21st Street E. around 12:30 p.m.

Officers were also sent to the office tower on 22nd Street, located a block away.

After that, police were called to a hotel on the 300 block of Circle Drive W. at around 1:30 p.m. The next delivery was made to another hotel on the 600 block of Cynthia Street. Police did not say where the fifth business was located.

No one has been hurt.

Between 40 and 50 fire department workers were involved in the emergency response.

Hackl said he had never seen a contamination scare of the same scale in Saskatoon.

"In the past we've had suspicious package incidents but never one that was to this magnitude where there is five different locations within a two-hour period."