Four people were injured in a Monday fire at a Manhattan apartment building that is being probed as suspicious, according to fire officials and law enforcement sources.

The blaze erupted around 3:20 p.m. on the first floor of the five-story building on East 63rd Street near 1st Avenue and quickly spread up to the roof, the FDNY said.

Three firefighters and one resident suffered minor injuries, fire officials said.

Firefighters extinguished the flames in about 90 minutes. Residents of the 16-unit building were displaced, fire officials said.

Law enforcement sources told The Post the fire is suspicious, and the fire marshal and police are looking for video of the blaze.

The owner of a uniform store on the first floor was required to get out of the space by Tuesday – the end of the month, sources said.