Brussels - Hundreds of Belgian lorries and tractors converged on the capital Brussels on Wednesday to protest against rising petrol prices, local media reports said.

The farmers and truckers were joined by taxi drivers, who tried to disrupt traffic on Brussels' inner ring-road.

Trade unions are calling on the government to introduce emergency measures aimed at keeping diesel prices low and farm prices high.

Walloon farmers planned to drive their tractors into the city's European quarter, where European Union leaders are due to hold their regular summer summit later this week.

Some 800 police officers were placed on alert, reports said. (dpa)