Hospital patients and others have been evacuated as an “out-of-control” grass fire burns near Saskatoon.

A state of emergency has been declared in the town of Biggar and the Rural Municipality of Biggar, due to smoke and poor air quality, according to Saskatchewan’s emergency alert system.

An area southwest of Biggar has been evacuated and the RCMP advise people to avoid the area because of a fire burning “out of control” since Monday night.

There is no confirmation yet on what caused the fire, which is moving away from the area thanks to a change in wind direction, according to an official. Showers are expected by the end of the week.

Jeanne-Marie de Moissac, reeve of the rural municipality, said there have been no injuries and no buildings have burned.

"We're exhausted," said Biggar fire chief Gerry Besse, after spending more than 20 hours battling flames that officials say have burned about 100 square km so far.

"This is going to take days to put out."

Crews and farmers battling the flames were trying to move cattle away from pastureland threatened by the blaze.

The Saskatchewan Health Authority has evacuated the Biggar Health Centre, including the hospital and long-term care facility, as a precaution. Patients have moved to beds in Rosetown and Saskatoon.

“A precautionary evacuation is called for the Biggar Health Centre, including the hospital and long term care facility,” Saskatchewan Health Authority announced in a tweet.

“Eight acute care patients and 53 long term care residents have been safely transported to alternate beds.”

Officials say residents in Biggar, located about 93 kilometres west of Saskatoon, have not yet been advised to evacuate but have been told to be prepared to leave the town if necessary.

A shelter has been set up at Biggar community hall for people with respiratory issues and the recreation complex in the village of Purdue.

“If the wind starts coming this way, it’s going to be not good,” one resident told CTV Saskatoon. “It can get worse fast.”

Farmers in the affected area have been using their machinery to create fire breaks to stop the advancing flames, and firefighters from outside the community were brought in to help emergency personnel.

De Moissac said water bombers are expected to attack the blaze, but she fears that a number of rural properties are still under threat.

"Emotions are high," she said. "We're not used to this. We're tinder dry ... that old grass just burns like gasoline.”

Biggar is not the only place in Saskatchewan to be hit with brush fires stoked by dry conditions and strong winds.

The number of active fires jumped from four to seven Tuesday with six of them now contained.

The RCMP warned that a grass fire burning near North Battleford, Sask., could pose a risk to Sweetgrass First Nation, Table Mountain and the village of Prongua.

According to the province, there have already been 23 fires this year, which is higher than usual.

Saskatchewan's fire commissioner is urging people not to light open fires. Crews are assessing how changing winds might affect the fires.

The investigation into the cause of the fire continues, with aircraft mapping the area to determine the point of origin.

--- With files from CTV Saskatoon’s Saron Fanel and The Canadian Press