KAMPALA, Uganda -- Police in Uganda fired tear gas at protesters demonstrating against high food prices and corruption in the capital.

stopped Monday's demonstration after participants tried to block the roads and appealed to others to join them.

Witness Henry Mukaga says some protesters threw stones at police and at motorists driving through the market where the protest erupted.

Participants said they were responding to a call from an opposition group to resume "walk to work" protests over food prices and corruption.

Those marches in March and April were among the most serious anti-government protests in sub-Saharan Africa this year. Human Rights Watch said police killed nine people during the marches.