A church van carrying three auxiliary police officers burst into flames Tuesday night after an unmarked NYPD cruiser slammed into it, sources said.

The church van was near the intersection of Belmont Avenue and Essex Street when a patrol car from Brooklyn North Anti-Crime collided with it around 11 p.m., according to law enforcement sources.

“I heard a big boom,” said witness Michael Edwards. “It looked like it was going to explode.”

After the victims were removed, the van erupted in flames.

Two police officers and two auxiliary officers were taken to the hospital in stable condition.

It was not clear what condition the fifth victim was in.