The special investigation cell probing the May 18 Mecca Masjid blasts grilled two terrorists in Hyderabad police custody to achieve a breakthrough in the twin blasts that rocked the city on August 25, claiming over 40 lives.

Police sources said the SIC team interrogated Shaik Nayeem alias Sameer, an accused in Samjautha Express bomb blast who was brought to Hyderabad in connection with the Mecca Masjid blasts and fake passport case in June, to ascertain his or other terrorist group's role in the twin blasts. 

Sameer, a resident of Jalna in Maharashtra, was nabbed by the West Bengal police while trying to cross the border along with two Kashmiris and a Pakistani.

The SIC also interrogated an ISI agent Mohd Abdul Sattar alias Annu alias Anwar, who was arrested at the Secunderabad railway station in June.

He had undergone training in Pakistan in 2004 in handling weapons and preparing explosives.

The SIC appeared to have some clues from the two terrorists, but it is not ready to divulge the details.

The city police also picked up seven youths, who allegedly had links with some banned terrorist organisations, including Students Islamic Movement of India, and questioned them. 

Meanwhile, special police teams left for Nagpur to grill Sohail of Amin Explosives, from where explosives were supplied to execute the twin blasts. Both the cases were being transferred to the SIC to speed up the investigations.