MUMBAI, April 23 -- Nearly 20 years after four powerful explosions killed 31 people and injured 312 in the Muslim-dominated town of Malegaon in Maharashtra, the Bombay High Court has discharged all four men accused by the National Investigation Agency (NIA) in the case. The development brings the case to a close, at least for now, but begs the questions: who was responsible for the 2006 explosions, and what was the motive? On Wednesday, a division bench of Chief Justice Shree Chandrashekhar and Justice Shyam C Chandak struck down the order of the special NIA court, which had framed charges against the four accused - Rajendra Chaudhary, Lokesh Sharma, Dhan Singh and Manohar Ram Singh Narwaria. The quartet had been charged under various sections of the Indian Penal Code (IPC) for murder and criminal conspiracy, and also under the Unlawful (Activities) Prevention Act (UAPA), a stringent anti-terror law. The four were arrested after a dramatic twist in the investigation, which had initially accused nine members of the banned terrorist outfit SIMI for the 2008 Malegaon blasts but later said right-wing extremists were behind the explosions. On September 8, 2006, four powerful bombs went off in Malegaon when people had gathered to offer Friday prayers in the afternoon, killing 31 people and leaving another 312 injured. In a matter of days, the Maharashtra Anti-Terrorism Squad (ATS), the first agency to probe the case, arrested nine members of the SIMI, claiming the blasts were their handiwork. In February 2007, the Central Bureau of Investigation (CBI) took over the investigation, and filed a supplementary charge-sheet against the nine SIMI members. The case took a dramatic turn in 2011, when the National Investigation Agency (NIA) took over the case and started working on the theory that the 2006 Malegaon explosions were the handiwork of Hindu right-wing extremists. The NIA claimed that Swami Aseemanand, a former RSS activist arrested in connection with two other bomb blast cases, had revealed that the 2006 Malegaon blasts had been orchestrated by Sunil Joshi, a former RSS pracharak, and his associates. Joshi, who was also allegedly involved in other terror cases, had been shot dead in December 2007, near his home in Dewas, Madhya Pradesh. The NIA then arrested four of his alleged accomplices and filed a separate charge-sheet against them, also seriously questioning the ATS case against the SIMI members. The special NIA court on April 25, 2016, discharged the nine SIMI accused from the case, and also ordered the release of two of them, Mohammad Ali Alam Shaikh and Asif Khan Bashir Khan Junaid, as they were still in jail at the time. The remaining seven had already been released on bail. On Wednesday, the case virtually came to an end as the high court has discharged all four accused arrested by the NIA....