NEW YORK — The FDNY is investigating the cause of a four-alarm fire inside a Manhattan restaurant early Tuesday morning that sent four firefighters to the hospital.

The flames started around 5 a.m. inside Dragon One located at 1843 First Avenue in Yorkville.

Fire officials say it started in the back of the restaurant before spreading to the front and then up to the second floor of the five-story building.

The FDNY says the ceiling of the first floor collapsed, injuring four firefighters.

Their injuries are all said to be minor.

No civilian injuries were reported.

The FDNY says a total of 165 firefighters and EMTs responded to the scene.