The Special Investigation Cell of the Andhra Pradesh police -- which is probing the Mecca Masjid blast and the twin blasts case -- has said that it will subject the detained brother- sister duo from Bangladesh to narco analysis tests.

Rizvan Ghazi, who strongly resembled the sketch of the Lumbini Park bomber prepared by the police, had been arrested after the Hyderabad twin blasts. Though he was overstaying in India illegally, the police could not find any evidence to link him to the blasts. However, during interrogations, Ghazi had revealed the names of two Bangladeshis who had disappeared suddenly after the blasts.
 
The police also arrested Ghazi's sister Rustamjah, and she will have to undergo a narco test as the police suspect that she is concealing vital information about the blasts.

The SIC maintains that though the duo may not be directly involved in the blasts, they may have important information about the people who were responsible for the blasts.

During the interrogation, Ghazi had revealed the names of two Bangladeshi nationals who were staying with him at Kishenbagh in Hyderabad. Through the narco tests, the police will try to elicit information about the two Bangladeshis as they had disappeared immediately after the blasts.

The police will have to obtain legal permission before going ahead with the narco tests. The two accused in the Mecca Masjid blasts have already undergone narco tests.

Meanwhile, the police have beefed up security in Hyderabad and other parts of the state in the wake of the recent terror threat. An anonymous letter sent to the police and the media on Friday night had warned of another terror attack in the city on September 25.