At least 18 people were injured in a Bronx fire early Tuesday, including three firemen, authorities said. One of the firemen was seriously injured.

The fire broke out at about 4:30 a.m. in the Claremont section of the Bronx on Washington Avenue at East 169th Street, FDNY officials said.

Authorities say 15 civilians suffered minor injuries and five of them refused medical attention at the scene.

The others were rushed to Jacobi Medical Center in stable condition.

Three firefighters were taken to the same hospital, authorities said.

One was listed in serious but stable condition, and the other two suffered minor injuries, officials said.

It took an hour and a half to get the fire in the 15-story residential building under control, authorities said.

The cause of the fire is under investigation.