Police have arrested a tenth suspect in the September 2011 New Delhi High Court bombing, and say many more arrests will come as they work to crack a home-grown terrorist threat.

On September 7th, 2011, a powerful bomb ripped through the reception area of the High Court in New Delhi. Callously placed near a security checkpoint where people were queuing for entry, it killed 11 people and injured at least 80 others.

No group claimed responsibility, but within days, counterterrorism authorities concluded the attack was perpetrated by members of the Indian Mujahideen (IM).

The same organisation was already under suspicion for possible involvement in a series of co-ordinated bomb blasts that struck Mumbai only months earlier, in July 2011, and has been implicated in a number of other cases.

On Tuesday (February 21st), officials of the Delhi Police Special Cell arrested their tenth suspect in the court bombing case – Mohammad Qafeel Ahmed, 50, an IM member in charge of recruiting young men and boys.

Many more arrests are likely to come, Delhi Police Deputy Commissioner Ashok Chand told Khabar South Asia.

"The IM is a huge operation and its [members] are involved in not just the Delhi case, but also in the February 2010 terrorist bombings in the German Bakery in Pune, Maharashtra, and a previous one in a cricket stadium in Bangalore," he said.

Qafeel Ahmed is "highly educated" and was responsible for indoctrinating fresh young entrants to IM with flowery jihadist rhetoric, he said.

"He used to brainwash local youths and recruit them to the terror outfit. He also provided safe hideouts for members of the outfit," Chand told Khabar.

Another alleged IM member, Mohammad Tariq Anjuman Ehsaan, was arrested in Bihar on February 4th. The 30-year-old father of two is a civil engineer with a job in New Delhi.

Police say that Ehsaan was the terror organisation's "thinking mind and financial planner", and had jumped bail after a 2003 counterfeiting arrest, local media reported.

While IM head Yasin Bhatkal eludes police all over India, his lieutenants are falling into traps at a rapid rate. In December, six IM members were arrested on a single day in co-ordinated sweeps in New Delhi, Madhubani (Bihar), and Chennai.

Even so, "IM represents an unprecedented threat for India", Ashok K. Behuria, Fellow at the Institute for Defence Studies and Analysis, told Khabar.

Unlike Lashkar-e-Taiba, the banned terrorist group that operates out of Kashmir, IM is a domestically based entity consisting of Indian Muslims who are highly knowledgeable of local conditions and have extensive contacts and support structures in the country.

"I had the opportunity of interviewing an IM operative once and learnt that though there is a high attrition rate in its ranks, meaning most recruits abandon the cause and rejoin normal life at an early stage, the ones who remain are highly intelligent and motivated," Behuria said.

"We are dealing with a very indigenous movement feeding on the economic problems of India's 150 million Muslims," he told Khabar, adding that most of the violence is perpetrated by disgruntled youths who perceive themselves as marginalised.

Shahroz Tariq Raza, editor of Urdu-language daily Daur-e-Jadeed, says the authorities need to keep in mind Muslim sensibilities in all of these investigations.

"A large number of people…are complaining of police high-handedness. This will only alienate Muslims further, something which IM would welcome," Raza told Khabar.

"It is absolutely vital to win the confidence of local residents if you wish to get their support in nabbing terrorists who live among them, most often by adopting false identities," agreed Digvijay Singh, a senior ruling Congress Party politician.

Prominent Muslim organisations in India have condemned IM and similar groups, saying it is against Islam to kill innocent people and that the violence is directed at tearing India apart.

In a joint statement issued after the July attacks in Mumbai, All India Ulema Council general secretary Maulana Mehmod Daryababdi and the president of the Jamiatul Ulema, Maulana Mustaqeem Azmi, warned that terrorism aimed to divide India's people along communal lines.

Four years earlier, following co-ordinated shooting and bombing attacks in the city that left over 160 dead, Muslims rallied to protest extremist violence.

"[Terrorists] claim to be doing this in the name of Islam. We have to tell them, 'Not in our name," CNN quoted activist Javed Anand as saying.

Muslim Ulema and intellectuals, meanwhile, issued a press release denouncing terrorism and stating that "murderers cannot be Muslims".