The FDNY is battling a four-alarm fire at a six-story apartment building on the Upper West Side, officials said Friday.

The blaze broke out around 8:20 a.m. at an apartment complex at the intersection of West 107th Street and Amsterdam Avenue, authorities said.

More than 100 fire and EMS personnel rushed to the scene as smoke and flames poured from the top floor, the FDNY said.

The blaze was upgraded to four alarms just before 9:15 a.m. as crews worked to contain the flames, according to the department.

Operations remain ongoing, and officials did not immediately report any injuries or say what caused the fire.

This is a developing story. Check back for updates.

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