JOHANNESBURG, South Africa (AP) _ Pledges by police to arrest anyone taking part in a threatened taxi blockade today caused organizers to call off the protest.

The National Taxi Drivers Organization, an alliance of black taxi drivers, said Thursday it would block major highways around Johannesburg and other cities to protest violence in the taxi industry.

But no blockade took place this morning, and the leader of the drivers' organization said the protest was called off to avoid clashes with police.

Taxi vans are the major means of transportation for poor blacks. During the apartheid era, the industry mushroomed into an unregulated system of rival syndicates that battle each other for routes.