South African police say an estimated 25,000 demonstrators shut down central Johannesburg for several hours Wednesday to protest the country's rising cost of food, fuel and electricity.

The mass demonstration was peaceful, but it disrupted businesses, commuter services, and street traffic until about noon local time.

The protest was part of rolling demonstrations organized by the Congress of South Africa Trade Unions (COSATU), the country's largest umbrella organization for trade unions.

Organizers said demonstrators are registering their "disgust" with the government and employers over high prices.

Among other things, protesters denounced plans to hike the electricity tariff by 27.5 percent.

The rolling demonstrations began earlier this year and are expected to continue indefinitely.

Increasing food prices have sparked riots in at least five African countries this year - Ivory Coast, Niger, Cameroon, Senegal and Burkina Faso.

United Nations officials have warned that food prices are likely to keep rising.

Some information for this report was provided by AFP.