NEW DELHI, Sept 2 (Reuters) - Four people have been arrested in connection with the bombing in May of a mosque in the south Indian city of Hyderabad, police said, adding they could be part of the same group involved in last week's twin bombings in the same city.

Two blasts occurred minutes apart on Aug 25 in two crowded parts of the city, an emerging information technology hub, killing 40 people and wounding about 80 others.

In another attack on May 18, 11 people were killed when a bomb exploded during Friday prayers at the historic Mecca Masjid in Hyderabad, the capital of Andhra Pradesh state.

"We have registered a case against 15 people...four have been arrested for transporting RDX explosives, from Bangladesh to India, which were used in the Mecca masjid blasts," Balwinder Singh, Hyderabad's police commissioner told Reuters.

"RDX was not used in last week's bombings but there is a possibility that the 15 people we have filed a case against could be part of the same outfit involved in the twin bombings."

Authorities suspect Islamist militant groups based in Pakistan and Bangladesh are behind the attacks. Both Islamabad and Dhaka have rejected the idea, saying Indian officials are jumping to conclusions.

Singh said the main suspect was Shahid Bilal of Harkat-ul Jihad Islami (HuJI), a Bangladesh group originally set up during Soviet occupation of Afghanistan.

AlertNet news is provided by