LAS VEGAS — A father was Christmas shopping when his four children and a young relative died in an Arizona house fire, police said.

The fire tore through the two-storey home on Saturday evening, authorities said on Monday, leaving no survivors.

Four children, ages 2, 4, 5 and 13 were siblings, while an 11-year-old was a visiting relative.

Officials are investigating the fire and have not released the names of the children or father.

The fire broke out in Bullhead City, 100 miles (160km) south of Las Vegas, just before 17:00 local time (1:00 GMT) on Saturday.

"The children's father reported to investigators that he was gone for approximately 2.5 hours to buy groceries and Christmas gifts," Bullhead City police said in a statement.

The preliminary investigation found that the fire originated in the downstairs entranceway, "most likely making it impossible for the children in the upstairs bedroom to get out of the residence safely", authorities said.

All five victims were found in the same upstairs bedroom. It appeared that the fire had made its way up the home's only staircase, blocking their escape.

Witnesses described frantic neighbors gathering hoses and ladders in an attempt to fight the fire.

"We pulled the garage door open, there was guys pulling stuff out," one witness, Patrick O'Neal, told local CBS News affiliate KTVK. "The closer we got to the door there was smoke starting to come into the garage and choking people out."

The neighbours were unaware that anyone was inside the home, he added. If they had known, he said they would have attempted a rescue.

Police say there were no adults home when the fire started.

A vigil is planned in a local park for Wednesday night, and a GoFundMe drive has raised over $14,000 (£11,000) as of Tuesday to help the families cover funeral expenses. — BBC