Thick smoke hangs over Stony Rapids Sunday as crews try to control the fire. (Submitted by Ken Sayies)

More than 1,100 residents of northern Saskatchewan are nervously watching from afar as forest fires continue to threaten their homes.

About 170 people from Black Lake were added to the list of evacuees Tuesday due to heavy smoke from the same fire that's threatening Sandy Bay, near the Saskatchewan-Manitoba border.

About 210 people from that community are staying at the university campus in Saskatoon, many of them with health problems including asthma.

"The smoke is really thick. You can't really see across the lake," said Nadine Sinclair, who left Sandy Bay on Monday.

Crews from Ontario and the Northwest Territories are helping to fight the fire. (CBC)

"I'm worried that we don't have a place to stay. Like if it burns, we don't have a place to stay, and there's other community members over there, and I'm worried about them to see if they can make it out."

Residents considered "high risk," such as seniors or young children, in the northeast community of Pelican Narrows are also scheduled to be taken to safety from their homes.

On Sunday, about 170 people were forced from Stony Rapids, close to the Northwest Territories-Saskatchewan boundary.

There's no word yet on when the evacuees will be able to return home.

More than 400 firefighters are battling the northern fires with help from crews and water bombers from Ontario and the Northwest Territories.

Haze from the fires has blown into Saskatoon and southern Saskatchewan.