Here are the latest developments in this big story:
A Pakistani national, Waqas was arrested at the Ajmer railway station yesterday on a tip-off. He is one of the most wanted in connection with several blasts in the country, including the serial blasts in Mumbai in July 2011 that killed 27 persons and injured over 130.
"We questioned him, got details of three others... got to know he was planning to meet his aides in Ajmer and plan another terrorist attack," said SN Srivastava, Special Commissioner of Police (Special Cell), Delhi Police.
While two among the trio, Mohd. Mahroof and Saqib Ansari, were arrested in Jaipur, the third, Mohd. Waqar Azhar, was nabbed in Jodhpur. A huge quantity of explosives, detonators and timers were recovered during the arrests.
Home Minister Sushil Kumar Shinde termed the arrests as a "big success", adding that Waqas' arrest "will help us in providing more links".
Cops, though, said that whether the planned "terror attack" was aimed at targeting the general elections that begin next month, needed further investigation.
The National Investigation Agency (NIA) had announced a reward of Rs 10 lakh on any information leading to Waqas' arrest.
After undergoing training at a Lashkar-e-Taiba-run terror camp run Waqas had entered India via Nepal in 2010, police said. He allegedly carried out several terror strikes - twin blasts in Hyderabad last year, Pune blasts in 2012 and the Jama Masjid shootout in Delhi 2010 - at the behest of Bhatkal. But he had been on the run ever since Bhatkal was arrested at the Indo-Nepal border in August last, police said.
Elaborating on the other three men, cops said that while Mahroof has an engineering degree, Waqar is studying engineering. Ansari, meanwhile, worked as computer and printing designer, police said.
Sources in Delhi Police say the trio belongs to IM's Rajasthan module, formed recently after the Darbhanga module in Bihar was busted following Bhatkal's arrest.
The NIA, which filed its chargesheet against Bhatkal last month, had claimed that the Rajasthan module was constantly in touch with Riyaz Bhatkal, the alleged IM founder based out of Pakistan.
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