Police made several arrests during a protest that erupted Friday in an impoverished suburb, after Algerian youths demonstrating in support of Palestinians in the Gaza Strip pelted riot police with sticks and stones. Hundreds of protesters clashed with riot police Friday in Algeria's capital during the unauthorized demonstrations. Tens of thousands of people, many waving Palestinian or Algerian flags, marched in at least two protests in Algiers, security officials said. Authorities banned any protests after Muslim prayers Friday for fear of violence or efforts by Islamist extremists to recruit support. "Hamas, Hamas," cried one group of marchers. "USA, terrorists," shouted another. Many wore Palestinian headscarves.