Thousands of people have fled their homes in northern Alberta where two out-of-control wildfires breached a town's defences and have burned down hundreds of buildings, including the town hall, police station and the radio station.

The RCMP said the Town of Slave Lake is on fire and many homes have burned down. The fire is apparently out of control, engulfing about half of the town.

The fires are in the north and east portion of the town, but winds are slowing down, giving officials hope the fires could be brought under control.

But residents are describing chaos.

"It's horrible; it's just going to spread because houses are ten feet apart," Myrna Franklin told CTV Edmonton. "Our house is out of town, I don't know if it's gone yet or not."

The Town of Slave Lake has issued a mandatory evacuation order and there have been reports that police are arresting anyone who does not comply.

"We are asking people who are able to travel and have the fuel to get to Athabasca, to leave the community," Mayor Karina Pillay said. "If they do not have transportation or fuel we are asking them to come down to the Northern Lakes College (evacuation centre) and register with us."

Earlier Sunday, the highways leading out of the town were blocked, forcing officials to tell people to flee to parking lots, the beach or any other wide-open green space.

But one highway is running late Sunday, and residents are now told to get out. Traffic is moving out, but at a slow pace.

There have been no reports of injuries yet, but communication is troublesome as power keeps going out. The local radio station was issuing emergency reports until it succumbed to fire.

There are about 200 firefighters in the town but conditions are lined up against them. Wind gusts of up to 100 kilometres an hour, have made water-bombers ineffective.

The first fire broke out to the southwest of Slave Lake, at about noon local time on Saturday.

The second blaze started to the east of Slave Lake in the Poplar Lane and Mitsue area.

The town has declared a local state of emergency and set up evacuation centres for those without a place to stay.

Slave Lake is located 250 kilometres north of Edmonton. About 7,000 people live in the town.

Fire conditions are "extreme" in Alberta, because of dry weather and high winds.

There are about 70 wildfires throughout the province, with the one near Slave Lake considered the worst.