Haze hung over Saskatoon Friday morning, as seen in this view from University Bridge. (Jennifer Quesnel/CBC)

The Saskatchewan Health Ministry is warning the public about smoke from British Columbia forest fires.

People in western and central areas of the province woke up Friday morning to haze in the sky and the smell of smoke. And southern regions got hazier as the day wore on.

In the afternoon, the health ministry put out an alert advising people with asthma and other respiratory and heart conditions to consider staying indoors with the windows closed.

Even people who are not at higher risk should avoid vigorous outdoor activity when there is heavy smoke in the air, said Dr. Saqib Shahab, Saskatchewan's deputy chief medical health officer.

Around 280 forest fires were burning in B.C. earlier this week, including this one near Pelican Lake in the province's Cariboo region. (B.C. Forest Service)

"When it becomes really hazy, so that you can't maybe see so far as a kilometre, that's when you know ... not to go for that afternoon jog," Shahab said. "Just wait a few hours till it clears up."

According to CBC Saskatchewan weather specialist Wayne Miscolzi, the smoke could last a few days, with visibility being only one to five kilometres in the more seriously affected areas.

"It's going to be quite noticeable today," Miscolzi said. "You can smell it out there … It's not quite as bad in the south as of yet, but that's probably going to change as well."

Visibility was especially bad around North Battleford and Saskatoon in the morning, but got worse in Regina by noon.

It's unusual for the smoke from B.C. to stay so thick from that distance, Miscolzi said, adding it will probably hang around for at least a couple of days.

At 2 p.m. CST, both Saskatoon and Regina were listed as "high risk" on the province's air quality index website.