Four people were killed on Sunday night in a motor vehicle accident on the R337 road between Aberdeen and Klipplaat.
Eastern Cape Transport Department spokesperson Khuselwa Rantjie says three men and a woman died instantly when their vehicle overturned.
Two other male occupants of the vehicle were taken to Aberdeen Hospital.
Rantjie says empty alcohol bottles were found in the vehicle and that authorities will be investigating a case of culpable homicide.
Sunday's incident brings to 11 the number of people killed in motor vehicle accidents on Eastern Cape roads over the weekend.
On Saturday four people were killed and three others were injured in an accident between a VW Polo and a minibus taxi on the N2 near Mthatha.
