Police, paramedics, fire crews and hazmat teams spent some four hours on Monday responding to two suspicious package deliveries in Saskatoon containing white powder that turned out to be harmless.

The two incidents were the latest in a series of white powder scares starting in November.

The packages were delivered to a downtown business at 10:25 a.m. CST and the Saskatoon Cancer Centre at 12:40 p.m., bouncing hazmat crews from one scare to another.

The first scare shut down a city block while police and the fire department's hazmat unit investigated the package, which contained a white, powdery substance.

The Saskatoon Fire Department has found that a white powder delivered to a Saskatoon business Monday was not hazardous. (Matthew Garand/CBC News)

The substance was inside an envelope delivered to a business on the 200 block of 4th Avenue S. near 20th Street. It was deemed to be non-hazardous.

​Not long after, emergency services received a call about another white powder package delivered to the Saskatoon Cancer Centre. The centre is located on the University of Saskatchewan campus.

The centre was not evacuated and patients were still able to enter and exit the building after emergency services isolated a safe corridor.

Scares tax resources

Monday's incidents were the fifth and sixth white powder scares in Saskatoon since November.

Saskatoon Fire Department assistant chief of communications Wayne Rodger said he did not know what was motivating the culprits.

I wouldn't call it frustration; it's our concern that while we're here doing this we could be doing other things. - Wayne Rodger, Saskatoon Fire Department

"Whether they get the attention they are desiring or not, I don't want to speculate," said Rodger.

"My concern is the resources needed to respond to these types of incidents. We take each and every one of these seriously because until we can prove or determine what the contents of these packages are, it has to be treated as a worst-case-scenario."

He said some off-duty firefighters had to be called in to backfill at stations while on-duty crews were responding to the scares.

"I wouldn't call it frustration; it's our concern that while we're here doing this we could be doing other things," said Rodger.

Series of scares

Last week, a suspicious package was delivered to Buena Vista School. The building was evacuated of more than 240 students before the material was found to be non-hazardous.

On March 16, the top floors of a Saskatoon office tower were evacuated as hazmat teams responded to another suspicious package. The substance inside the package was deemed to be benign.

One white powder scare at a UPS office in January turned out to be drugs.

And in November, a major incident cost police and fire crews $66,000. That hoax sent police and more than 40 firefighters to five separate businesses across the city.

Alexa Emerson pleaded not guilty to charges of mischief and uttering threats in relation to the incidents. She has yet to go to trial.