Reports from Tunisia say at least four people have been killed during new clashes between police and demonstrators. Protesters defied a government-ordered curfew in the capital, Tunis, and police fired tear gas at rock-throwing demonstrators angered by high unemployment and food prices. Tunisian officials say unrest across the country has killed 23 people in the past few weeks. Opposition and rights groups say the death toll is more than 50. Witnesses in Douz, south of the capital, said at least three people were killed on Wednesday in clashes between police and demonstrators. The U.N. High Commissioner for Human Rights has urged the government to stop security forces from using excessive force against protesters. Navi Pillay also has urged Tunisia to launch a transparent and credible investigation of the unrest.