LOS ANGELES — Some residents slid down knotted bedsheets or clambered down people standing on one another’s shoulders to flee a raging Christmas night fire that injured six people and badly damaged a residential motel near downtown Los Angeles, authorities said Friday.

Two of the injured suffered critical burns and smoke inhalation, Los Angeles Fire Department spokesman Erik Scott said. Five people were hospitalized, and the injured ranged in age from 28 to 73.

The fire, which broke out about 6 p.m. Thursday, was traced to a kitchen in one of the three-story motel’s 135 units.

“First-arriving firefighters were immediately met by multiple challenges as they saw residents trying to escape from smoke-filled second-floor windows by climbing down bedsheets tied together or on human ladders of people standing on each other’s shoulders,” Scott said.

He said firefighters had to help several people out of the burning building, including some in wheelchairs.

As they did so, other firefighters dragged hoses through corridors and up stairwells while still others used chain saws to cut holes in the hotel’s roof to allow the flames and smoke to vent.

It took approximately 100 firefighters about 20 minutes to douse the blaze, Scott said. About 25 units were damaged by fire, smoke and water.

Senior arson investigator David Liske said the fire originated near a stove in one of the hotel room’s kitchens.

“While the cause of the fire appears to be accidental, the investigation will continue,” Liske said.

Scott said the hotel’s smoke alarms worked properly, alerting residents to the blaze.