Indian Prime Minister Manmohan Singh is defending a police crackdown on an anti-corruption protest led by a popular yoga guru.

Authorities used batons to break up Baba Ramdev's peaceful hunger strike during a pre-dawn raid early Sunday, injuring dozens of people. The mass fast was part of a populist campaign to fight corruption.

India's Supreme Court questioned the government action on Monday.

Prime Minister Singh later told reporters that it was “unfortunate” that the police operation had to be conducted, but there was “no alternative.”

Mr. Singh added that the government is serious and concerned about corruption and “black money,” but there is no “magic” solution to the problem.

Baba Ramdev began his hunger strike to demand the government bring back money illegally stashed overseas and introduce tough anti-corruption legislation. He wants the death penalty for corrupt officials.

Police say Baba Ramdev did not have permission to hold such a large protest and that Sunday's massive gathering in the Indian capital could have posed a law and order problem. The government says the guru went back on promises to call off the hunger strike.

On Monday, India's main opposition Bharatiya Janata Party joined the Supreme Court in questioning the crackdown on the protest.

BJP leader Lal Krishna Advani demanded the government convene a special parliamentary session to explain the police action.

Baba Ramdev is continuing his campaign in Haridwar, the Hindu holy town in northern India where he was taken by police after being detained. He vowed Monday to build his campaign into a national movement.

The yoga guru's protest began two months after the government was caught unaware by massive popular support for another anti-graft campaign started by a social activist (Anna Hazare) in April.

India's ruling Congress party has been under pressure following a series of corruption scandals. Authorities are currently investigating whether the organizers of last year's Commonwealth Games in New Delhi received kickbacks amounting to billions of dollars. And the Indian government says it lost up to $40 billion in revenue due to the sale of mobile phone licenses at below-market prices.