Indian Prime Minister Manmohan Singh is criticizing a hunger strike by a leading anti-corruption activist as misconceived, while fresh protests sweep across India for a second day.

In a speech to parliament Wednesday, Prime Minister Singh said Anna Hazare's protest may be inspired by high ideals, but that Hazare cannot be allowed to force lawmakers to sign his own version of anti-corruption legislation. As some lawmakers jeered, Mr. Singh said such a path was “fraught with grave consequences for our parliamentary democracy.”

Indian police placed Hazare and over 1,000 of his followers in “preventative custody” on Tuesday, after they refused to abandon plans for a protest and hunger strike in a public park aimed at convincing India's government to pass tougher anti-corruption laws.

On Tuesday night, police allowed Hazare to leave, but he refused, saying he would continue his fast behind bars until authorities allowed the protest to take place without restrictions.

Protesters on Wednesday gathered outside New Delhi's Tihar jail, where Hazare is being held, shouting “down with corruption.” Meanwhile, thousands marched from the India Gate memorial through the Indian capital shouting slogans in support of Hazare. Demonstrations were also held in the country's financial hub, Mumbai, and cities throughout the south.

Earlier this month, Mr. Singh's ruling Congress party introduced an anti-corruption bill in parliament that would create a civil organization, or lokpal, with the powers to investigate ministers and bureaucrats. But Hazare rejected the bill and called for parliament to pass his own version, saying it would do more to hold the prime minister and judicial branch accountable.

In a statement released after his detention, Hazare vowed to continue the protest movement, telling supporters that the “second freedom struggle” had begun. He also urged them to keep the movement non-violent.

Popular outrage over corruption in India has grown steadily over the past year as reports of one high-profile corruption scandal after another have made headlines in national media. They include the sale of telecommunications licenses at below market value and numerous financial irregularities in India's hosting of last year's Commonwealth Games.