Description:Tear gas rises as protesters clash again with riot police near Cairo's Tahrir Square, and opponents of President Mohamed Mursi rally for a day of mass action. Many in the country are angry following a decree by President Mursi last week that prevents legal challenges to any decision he makes until a new parliament is elected. The opposition, accusing Mursi of appointing himself a modern-day Pharaoh, is pressing ahead with Tuesday's protest to demand the scrapping of the decree.(0:54)