Hyderabad has a large Muslim population
Police in the Indian state of Andhra Pradesh must be prosecuted for torturing Muslims detained after bomb blasts last year, a rights group says.
Human Rights Watch warned of the risks of stigmatising and alienating "an entire community".
The state government admitted last week that 21 men had been tortured and would each receive $600 in compensation.
A series of blasts in May and August 2007 killed nearly 60 people in the state capital, Hyderabad.
The authorities in Andhra Pradesh detained nearly 100 men for questioning soon after the bomb attacks in the capital, Hyderabad, but the government last week admitted that 21 of the suspects had been tortured.
"Acknowledging torture and providing compensation is a good first step," said Meenakshi Ganguly, senior South Asia researcher at Human Rights Watch.
"But the government has to prosecute those responsible so that those who use torture will not get away with it."
Nine people died in Mecca Masjid blast in 2007
In a press release, Human Rights Watch said the detainees were stripped, hung upside down, severely beaten, subjected to electric shocks and otherwise ill-treated.
"They were also threatened with the torture of their relatives, particularly female relatives," the statement said.
"The police response to terrible bombings has been to round up people, simply because they happen to be Muslim, and to torture them in the hope of securing information or confessions," Ms Ganguly said.
"This stigmatises and alienates an entire community and makes counter-terrorism efforts even more difficult."
At least nine people were killed in the blast during Friday prayers at the Mecca Masjid, one of India's biggest mosques, in May last year.
In August 2007, nearly 50 people died and dozens were injured in two explosions in the city.
Hyderabad is one of the biggest cities in southern India and has a large Muslim population, many of whom live in the congested old city where the mosque is located.