Swedish firefighters were battling Tuesday a massive forest fire described as the worst in living memory which has engulfed homes, left one man dead and sent hundreds fleeing their homes.

France and Italy were sending in specialised firefighting aircraft to help douse the fast-moving blaze ravaging a vast area in central Sweden.

More than 1,000 people were evacuated from the hardest hit region around the town of Sala on Monday night, according to local media, and thousands more were put on alert on Tuesday to prepare to leave their homes at short notice.

Firefighters found one man burned to death on Tuesday on a small road near Sala, which lies around 170 kilometres (100 miles) northwest of Stockholm.

And a truck driver with a timber cargo was admitted to intensive care with severe burns when his vehicle was encircled by flames.

"It was thick with smoke and I heard the forest was blazing. They were water bombing just above where we live," Tommy Persson, one of the evacuees, told Swedish news agency TT.

Hot, dry and windy weather -- as well as difficulties in reaching remote parts of the forest -- have made it particularly hard to control the blaze, according to Lars Gunnar Strandberg at the national emergency services agency MSB.

"On Monday night it was moving at a pace of 30 metres per minute," he told public broadcaster Sveriges Radio, adding that the area has thousands of hectares of thick forest, often lacking natural barriers like wide roads or rivers.

About 100 volunteers helped firefighters as 13 helicopters struggled to navigate through thick smoke to drop water on the worst affected area, but the fire remained out of control after growing steadily over the course of five days.

The fire was estimated to be raging on an area covering about 100 to 150 square kilometres (40 to 60 square miles).

On Monday, Sala had the hottest temperatures in more than two decades at over 34 degrees Celsius (over 93 degrees Fahrenheit) with little prospect of rain in the coming days.

The emergency services agency said it will take several weeks to completely quench the fire and that it was considering burning sections of state-owned and private forests to cut off the progress of the blaze.

But first more water was needed to lower the temperature and allow firefighters better access.

Two Italian and two French firefighting aircraft are expected to arrive in the area on Tuesday.

The cause of the blaze is unknown but minor forest fires are common in Sweden in the summer months.