About 5,000 people remained out from their homes Tuesday as wildfires continued to burn in north-central Alberta.

The evacuees included people from Wabasca, the Bigstone Cree First Nation and two municipal districts in a rural area north of Edmonton.

Agriculture and Forestry Minister Oneil Carlier said he hopes people will abide by a provincewide fire ban.

"Most of the province is under a high to severe fire threat and it is incredibly important at this time that we all do everything we can to keep people safe."

The Municipal District of Opportunity and the Bigstone reserve, along with the MD of Lesser Slave River, were under states of local emergency, which allow local authorities to order evacuations and control travel in affected areas.

An evacuation order was lifted Tuesday afternoon for the area of the Old Smith Highway, and about 300 residents were expected to begin returning over the next day.

However, those who returned were told to remain on a 30-minute evacuation notice, and Chief Jamie Coutts of the Lesser Slave Regional Fire Service advised they should not disable or remove any sprinklers on their property.

As of Tuesday afternoon, there were 70 fires burning in the province; 20 were considered to be out of control.

The fire about 20 kilometres east Slave Lake was estimated to be five square kilometres in size. The fire near Wabasca and Bigstone was about two square kilometres.

Wildfire officer Geoffrey Driscoll said fire crews, along with helicopters and air tankers, have been working hard to keep those fires from growing much larger. But he said that could change depending on the temperature, wind and humidity.

Many new fires were started Monday night by lightning, and more lightning was forecast for late Tuesday.

"We're going to hope that it comes with some rain but likely it's not going to come with enough to make a difference," he said.

A long, dry spell in the area has been the biggest concern.

"We haven't seen very much significant rain since the snow left back in the spring and that's what's causing the high fire hazard in many of these areas. And that's also what's causing the fires to get big fast."

More than 600 firefighters were working directly on the wildfires and the government was considering putting a call out for reinforcements. About 100 firefighters from Ontario and water bombers from Quebec have already made the trip west to help.

The wildfires also forced more evacuations from oilsands sites in the Cold Lake area Tuesday.

One fire, about 100 square kilometres in size, was threatening the only access road into the facilities.

Statoil Canada said that it was voluntarily removing non-essential staff from its Leismer project south of Fort McMurray. Company spokesman Peter Symons said Leismer continues to produce oil, but only about 30 of the project's 185 workers remain at the site.

MEG Energy was also getting non-essential staff and contractors away from its Christina Lake facilities.

Cenovus Energy and Canadian Natural Resources earlier shut down projects as a safety precaution, sending about 2,000 workers home.

Meanwhile, officials in Edmonton issued a precautionary air quality advisory for the city due to smoke from the wildfires.

Alberta Health Services said the advisory could last for weeks.