India News :India News : Terming the communal riots in Muzaffarnagar a "big tragedy", Prime Minister Manmohan Singh, during a visit to the violence-hit Uttar Pradesh district along with Congress chief Sonia Gandhi and party vice president Rahul Gandhi on Monday, called for punishing the guilty.br Manmohan Singh asked the Uttar Pradesh government to ensure safety and rehabilitation of the people who were displaced.br A grim faced Manmohan Singh spoke to officials as he walked through Bassi Kalan village and later Tawli amid tight security.