New Delhi: A Hyderabad court on Monday acquitted five accused in the Mecca Masjid blast for lack of evidence, provoking fresh allegations that the National Investigation Agency was deliberately diluting cases against Hindu terror accused.

Questions were raised also when, shortly after passing the verdict, special NIA judge K. Ravinder Reddy submitted his resignation citing "personal grounds". Hyderabad MP Asaduddin Owaisi called it "very intriguing".

A senior judicial officer said Reddy had declared that his resignation, which had apparently not been accepted till tonight, had nothing to do with the judgment.

After initial investigations by local police, the CBI had taken the case over and filed a chargesheet. But in 2011, the probe was transferred to the NIA, which named 10 Hindu suspects.

One accused, Sangh activist Sunil Joshi, was murdered during the probe. Sandeep V. Dange and Ramchandra Kalsangra are in hiding while investigations are continuing against the remaining two. Only the five who have been acquitted were tried.

Aseemanand, 66, and Rateshwar were already out on bail. Gupta is serving a life term for the 2007 Ajmer Sharif blast. The other two will now be freed from jail.

According to Aseemanand's counsel J.P. Sharma, the court ruled his client had made his alleged confession, on which the case was based, under duress.

Aseemanand, a saffron-clad preacher, was born Naba Kumar Sarkar at Kamarpukur village in Bengal's Hooghly district and worked with the Vanvasi Kalyan Ashram in Purulia and Bankura. He is known for his anti-minority speeches.

In March last year, the NIA had absolved him in the Ajmer blast case. He remains an accused in the 2007 Samjhauta Express bombing.