Two gunmen opened fire on two plainclothes police officers who were sitting in their vehicle at a red light, leaving both officers wounded and spurring an intense manhunt for the shooters.

Camden County Prosecutor Mary Eva Colalillo said the shooting occurred around 8:30 p.m. Tuesday in Camden, which is located just across the Delaware River from Philadelphia.

One of the two detectives was able to return fire, but it's not clear if either gunman was shot in the exchange. County authorities remained in communication with hospitals in the region in case either shooter sought treatment for injuries they may have suffered.

The detectives — a man and a woman whose names were not released — both were wounded and taken to a hospital for treatment. Each was listed in stable condition on Wednesday and both are expected to survive.

Authorities declined comment on the extent of the detectives' injuries, but media reports said the male detective was shot twice in the arm while the woman was shot in the hand.

"(They) essentially were ambushed," Camden County Police Chief J. Scott Thomson told reporters at a news conference late Tuesday night. "A male walked up and began opening fire. We have anywhere between 10 and 25 rounds that were fired at the officers."

Police continued to search Wednesday for the men involved in the "unprovoked" attack, authorities said.

"Maybe they did know they were police officers and that's the reason why they did it. Maybe they thought they were somebody else. We'll find that out as the investigation unfolds," Thomson said.

The shooting occurred on National Night Out, an event designed to bring local police and the communities they serve together.

The two detectives have both been placed on paid administrative leave while the investigation continues. This is standard procedure following police-involved shootings.