NEW DELHI, April 16 (Xinhua) -- An anti-terror court in India Monday freed five men, including a Hindu saint, accused of engineering a bomb blast in one of the country's biggest mosques in the southern city of Hyderabad some 11 years ago.

The explosion at the historic Mecca Masjid (mosque) took place during Friday prayers on May 18 in 2007, claiming the lives of nine people and injuring over 50 others. Five others were also killed in police firing during riots that followed the blast.

The court acquitted all the accused, citing lack of evidence. The anti-terror National Investigation Agency (NIA) has failed to prove anyone's guilt, according to the court.

"The NIA had taken over investigation in the case from the Central Bureau of Investigation in 2011. But even after seven years, the anti-terror agency has failed to prove the involvement of the accused in the bomb blast. So, all were acquitted by the court," said a lawyer.

A total of 10 men, allegedly belonging to right-wing Hindu groups, including saint Swami Aseemanand, were initially named as accused in the case by NIA. Among the 10 suspects, one was killed during the investigation, two others went missing, and the probe is still on against two others, leaving five of them acquitted.

More than 200 witnesses testified during the trial and as many as 400 documents were exhibited.

However, Hyderabad's Muslim parliamentarian Asaduddin Owaisi slammed the NIA for the acquittal of the five accused in the 2007 Mecca Masjid blast.

"The NIA deliberately did not pursue the case," he told the media.

Hyderabad is home to a large number of Muslims, many of whom live in the congested old city where the mosque is located.