(Reuters) - Five children died and other people were rescued from an early-morning fire at a home that operated as a daycare center in Erie, Pennsylvania, on Sunday, officials and news media reported.

Two teenaged boys escaped by climbing out a window, news media reported. They then screamed for help, alerting neighbors.

Erie Fire Chief Guy Santone told local news media that as many as eight people had been trapped, including the five children, the two teenagers and one adult. No official count was released early on Monday.

Four of the five children were staying at the center while their parents worked overnight, news media accounts said. It was unclear early on Monday whether the fifth child belonged to the family that lived in the house.

One neighbor heard the screams of the teenaged boys and tried to get into the first floor of the house but was forced back by the fire, Erie News Now reported.

When firefighters arrived about 1:15 a.m. at the house the first floor was engulfed and flames were funneling out of every window, news media reported. The fire was so hot it melted the vinyl siding off houses next door.

Firefighters tried to revive the children at the scene, witnesses told local news media.

The adult suffered burns and smoke inhalation and was taken to a Pittsburg hospital by a helicopter ambulance, Erie News Now reported.

The cause of the fire remained under investigation by police and fire officials. Santone told local news media an electrical overload on the first floor living room may have been the cause.

There was only one smoke detector in the house and that was in the attic of the three-story structure, Erie Chief Fire Inspector John Widomski told the news media.

Citing their grandmother, GoErie.com reported the victims included four siblings - two girls and two boys - aged 8, 6, 4 and 10 months old.

Photos posted online showed people leaving balloons and teddy bears in a makeshift memorial just outside of the yellow police caution tape roping off the burned house.