Two men are on the run after a Brooklyn deli worker was shot in the back of the head Saturday night in Flatbush.

Police say the 18-year-old victim was shot following an argument between two other man at the deli on Nostrand Avenue around 6 p.m.

The victim was transported to Kings County Hospital where he was listed in critical condition.

Police are still looking for the two suspects who fled the shooting -- no descriptions have been released by the NYPD.