UNBUMBUVU, South Africa (AP) _ Thousands of Zulu and Pondo tribesmen battled each other with hatchets, homemade guns and knives for the past three days, leaving 40 dead and scores wounded, police said Wednesday.

The fighting was in Natal province on South Africa's eastern coast, where Pondo lands are next to Zulu territories.

Police said they did not know what caused the latest flare-up in the ancient rivalry between the two tribes.

In the past, battles have started over such issues as a stolen cow or a suspected sexual transgression.

About 2,000 Zulus and 3,000 Pondos were involved in the fights, police said. They gave no breakdown on the deaths.

The Zulus, who number about 6 million, are the largest ethnic group among South Africa's 24 million blacks.

907EST