More than 15,000 people joined an angry but peaceful protest in central London on Saturday against the Prophet Muhammad cartoons that have infuriated many in the Muslim world. Buses brought participants from cities around Britain to gather in Trafalgar Square, and they later marched through central London to Hyde Park, from where the crowd began dispersing late in the afternoon. "Free speech cheap insults," read some placards. "How dare you insult the blessed Prophet Muhammad?" asked another. Speakers shouted from the podium and the crowd yelled back as the demonstration grew increasingly angry. Police said about 15,000 people were present, and there were no reports of violence or arrests. Organizers estimated 40,000 people marched.