Four people were killed in a head-on car crash in Gloucester Township late Sunday afternoon, officials said Monday. Two others were critically injured.

Police said it was just before 5 p.m. when a car driven by Richard Mason, 53, and a car with Panagioti Ramoundos, 43, behind the wheel and carrying four passengers collided on Sicklerville Road near Dunlin Way.

Both drivers, who were killed, lived a few blocks apart on Wilson Drive in neighboring Winslow Township, officials said..

Two passengers in Ramoundos' 2008 blue Toyota Camry — Anastasia Ramoundos, 80, and Demetrios Ramoundos, 77,  who lived with the driver and are believed to be his parents — were fatally injured in the crash.

Jack Kalogridis, 59, of Gloucester Township, and Betty Kalogridis, 74, of Williamstown, were the other passengers in Ramoundos' car. Both were in critical but stable condition at Cooper University Hospital in Camden, police said.

Mason was driving a tan 2005 Toyota Camry.

Police Chief Harry Earle said that it was too early to know what caused the crash, and it was still under investigation.

He asked anyone who might have witnessed the crash to contact investigators at 856-228-4500.