India's Prime Minister Manmohan Singh has called on communist rebels to halt violence and seek their goals through peaceful means, such as elections. Mr. Singh also warned no civilized society can tolerate extremism of any form, and that the government will have no other option than to fight such groups and their ideology of hatred. Mr. Singh made the comments during a brief stop today (Sunday) in the southern state of Andhra Pradesh, where suspected Maoist rebels killed ten people after an Independence Day rally. Indian Maoists are active in eight states. They say they are fighting for the rights of poor landless agricultural workers. New Delhi says they also have links with Maoist rebels fighting to topple the monarchy in Nepal.