Children of the victims of 1984 Bhopal gas tragedy, a gas leak from a Union Carbide pesticide plant that killed at least 3,500 people, stand in a queue after being stopped by the police from marching towards prime minister's office (PMO) during a protest in New Delhi June 27, 2011. Dozens of children from central Indian city of Bhopal on Monday protested outside PMO demanding medical care, rehabilitation and poison free environment, a media release said. REUTERS/Adnan Abidi (INDIA - Tags: CIVIL UNREST DISASTER ENVIRONMENT)