Almost after 24 years, the Central Bureau of Investigation (CBI) arrested on Friday the main accused in the 1993 bombing of Rashtriya Swayamsevak Sangh (RSS) headquarters in Chennai, in which 11 people were killed. The blast was carried out by proscribed terrorist organisation Al Ummah. It was founded in Tamil Nadu in 1993, a year after the Babri Masjid demolition.

The accused, identified as Mushtaq Ahmed, a top leader of Al Ummah and the main accused of the 1993 bombing, was arrested in the morning from the outskirts of Chennai on Friday, said CBI spokesperson Abhishek Dayal.

The agency had been looking for 56-year-old Ahmed since the beginning and had also announced a reward of Rs 10 lakh for providing credible information about him. Ahmed had allegedly procured the explosive material for assembling the bomb and provided shelter to other accused persons.

The blast on August 8, 1993 was triggered using RDX. It brought down the multi-storeyed RSS office at Chetpet in Chennai, claiming 11 lives.

CBI took over probe in 1993 and filed a charge-sheet against 18 persons under the stringent provisions of the Indian Penal Code, Explosive Substances Act and Terrorist and Destructive Activities (Prevention) Act (TADA). In 2007, a TADA court in Chennai in 2007 convicted 11 persons and awarded life terms to three after a 12-year trial. The court also acquitted four persons, including SA Basha, founder of the banned Al Umma, for lack of evidence against them. Imam Ali, a suspected ISI agent who had escaped from custody in Madurai, was gunned down in Bangalore in an encounter with the police on September 29, 2002. Another accused, Jihad Committee founder Palani Baba, was hacked to death by suspected RSS sympathisers on January 28, 1997. Of the 431 witnesses, 224 were examined during the course of the trial which commenced on August 7, 1995.

However, the main accused Ahmed -- who did not face trial as he could not be arrested -- was on run and the agency was looking for him. Once the Al Ummah, started a South India-based 'Base Movement', owing allegiance to Al Qaeda, hunt for Ahmed intensified and finally he was nabbed.