Two women whose bodies were found in the back seat of a crashed car were killed by the driver of the vehicle, who died in the accident, police said Monday.

The two women were sisters, aged between 50 and 60, and were each killed with ax blows to the head, said Krzysztof Jarosz, a spokesman for Poznan police. The 60-year-old man who had driven the car, identified as Mieczyslaw N., was the husband of one of the women, likely motivated by a "family disagreement," he said.

According to the police investigation, the man killed the women in their respective homes Saturday night, then wrapped their bodies in plastic bags and blankets and put them in his car, Jarosz said.

On Sunday he visited another person, with whom he left some US$3,000 (euro2,000) and various documents, and drove off — then crashed into a tree on a country road near the western city of Poznan.

Police were still trying to determine whether the crash was a suicide or an accident, Jarosz said.