Vancouver fire officials say a faulty electrical connection to old Christmas lights is responsible for an overnight fire that killed three men and injured a fourth.

The fire broke out in the rear of the East Vancouver home, which is used as a low cost rooming house for seven men, just before midnight.

Three residents managed to escape the fire but the remaining four were rescued by fire fighters.

"According to our investigator it was somewhat of a flophouse, and unfortunately three people have succumbed to the fire," Vancouver Fire Department Capt. Gabe Roder said.

In Pictures: Vancouver house fire

Another man was rushed to Vancouver General Hospital, where he remains in stable condition.

Investigators say the fire sparked from a short circuit in the electrical system caused by a faulty extension cord connected to an old set of holiday lights.

There were smoke alarms in the home but it is still not known if they were working.

Roder said Vancouver Fire has responded to the home 21 times since 2007, mostly medical emergencies.

There was one small fire at the home in 2008. Officials say it was caused by smoking-related materials.

Neighbour Matthew Friesen told CTV News one of the residents had panhandled outside of a local drugstore store for the last three years.

Friesen described the men as "a little bit down and out."

"I've chatted with them a few times and yeah they seem like good guys," he said. "[This is] not a good beginning to the Christmas season that's for sure. It's a sad story."

The names and ages of the victims have not been released.