A massive forest fire that continued to burn Sunday in British Columbia's Interior had doubled in size in just two days, prompting officials to ask for even more resources to battle the blaze.

The fire near Tyaughton Lake, west of the community of Lillooet, had doubled in size since Friday, growing to more than 4,000 hectares, said fire information officer Mary Anne Leach.

"That's due to some pretty aggressive fire behaviour (Saturday) afternoon and overnight," said Leach.

Leach said there were 200 firefighters and 11 helicopters battling the blaze, and officials had requested even more resources, particularly additional helicopters.

"We're hitting it as hard as we can," said Leach. "That's a huge number of resources on a fire like this."

Leach said the fire had been growing as strong winds fuelled the flames -- and she said those winds could posed similar problems on Sunday.

The fire, which was discovered on May 29, is believed to have been caused by people, and officials were investigating precisely how it started.

Some residents who were ordered to leave their homes have since been allowed to returns, but several areas remained under evacuation orders.

The orders were in effect in Marshall Lake, Liza Lake, Carol Lake, Mud Creek, Tyaughton Lake and Gun Creek Road.

Three other communities -- Gun Lake, Gold Bridge and Bralorne -- were on evacuation alert.

Officials have said several people under evacuation orders had chose not to leave.

The RCMP issued a statement on Sunday stressing that evacuation orders are mandatory and that officers would be enforcing the orders and restricting access to those areas.

The Mounties say officers will enforce road and bridge closures to prevent people from returning to their homes until the orders are lifted.

The release says violating the evacuation orders is illegal and hampers efforts by diverting resources away from battling the blaze and preventing helicopters from dropping flame retardant on areas where people might be.

In addition, the release says emergency crews won't be deployed to rescue anyone who runs into trouble in an area that is subject to an evacuation order.

There are more than a dozen fires bigger than 10 hectares burning across B.C., according to the province's Forests Ministry's website.

The largest is in northern B.C., where a fire at the junction of the Liard and Smith rivers had grown to more than 16,000 hectares.

There were nearly 100 firefighters and five helicopters at work fighting that fire, and 60 people were under an evacuation alert.

With files from The Canadian Press