Fire broke out in a Tennessee apartment building early Tuesday, killing four people and injuring at least eight others, most of them children, a fire department official said.

The four who died were all believed to have been in the same apartment, Lt. Keith Staples said. Three of them were children, he said.

By the time firefighters reached the early morning fire, the two-story building was in flames, officials said. It was not immediately clear how the blaze started.

Authorities said eight people — five of them children — were taken to hospitals.

Some residents are reported to have jumped from balconies to escape the flames.