The retrial of a controversial case tied to one of the worst massacres during anti-Muslim riots in western India two years ago begins today amid tight security and threats from Hindu hardliners. The Supreme Court ordered a fresh trial after 21 Hindu defendants were acquitted among claims witnesses were threatened by officials. The court ordered the trial to be moved from Gujarat state in the northwest, south to Mumbai, to ensure impartiality. Police have arranged special security for the new trial following threats by several Hindu extremist groups. More than 2,000 Muslims were killed in riots after a Muslim mob allegedly set a rail compartment on fire, killing 58 Hindus in Gujarat in February, 2002. The former ruling party of India, the nationalist Bharatiya Janata Party, had a tight grip on the state and the ensuing Hindu backlash was described as a state-sponsored pogrom. Twelve Muslims hiding in a bakery in Baroda, 100km from the state capital, Ahmedabad, were burned alive when Hindus set it alight. The bakery-owner's daughter, Zahira Sheikh, who had a miraculous escape, became the star witness at the first trial. But she retracted a police statement in court and refused to identify the alleged killers. In total, 36 prosecution witnesses refused to give evidence. The case collapsed and the 21 Hindu defendants were acquitted. An uproar ensued as rights groups accused the BJP of systematically sabotaging trials involving Hindu defendants and Muslim victims. Even India's state-appointed National Human Rights Commission, headed by a retired Supreme Court chief justice, branded the acquittals a miscarriage of justice. The case took an unexpected turn after civil rights activists helped Ms Sheikh file a petition in the Supreme Court stating that she and other witnesses were pressured by BJP leaders. During the hearings, it became clear that Gujarat's BJP government, public prosecutors and provincial judiciary were working together to deny justice to Muslim victims. The court ordered a retrial and the accused rearrested. New prosecutors have also been appointed.