Indian police have arrested a prominent social activist just hours before he was preparing to push ahead with a public hunger strike to demand tougher anti-corruption legislation.

Activists say Anna Hazare, 74, was detained by plain-clothes police officers early Tuesday at a New Delhi apartment, as hundreds of his supporters protested outside.

Police say they placed Hazare and several other activists in “preventative custody” to maintain order and prevent a banned protest, but have not yet charged him with a crime.

The activist had threatened to resume a “fast unto death” on Tuesday after complaining that a proposed anti-corruption bill introduced earlier this month would not sufficiently keep the prime minister or judiciary accountable.

A similar hunger strike by Hazare in April fueled a media frenzy and a wave of popular demonstrations across India.

In a statement released after his detention on Tuesday, Hazare vowed to continue the protest movement, telling supporters that the “second freedom struggle” had begun.

Late Monday, police detained dozens of Hazare's supporters who were preparing to take part in the public fast. Police banned the gathering, saying Hazare had not agreed to limit his hunger strike to three days or limit the gathering to 5,000 people.

Earlier Monday, Prime Minister Manmohan Singh vowed that his government will take the “strictest possible action” to counter corruption. Mr. Singh also appealed to Hazare to abandon his hunger strike, saying those who disagree with the government should not resort to protests and hunger strikes, but instead make their views known through parliament, political parties and even the media.

Several high-profile corruption scandals have made headlines in India over the last year. They include the sale of telecommunications licenses at below market value, numerous financial irregularities in India's hosting of last year's Commonwealth Games, and land and real estate projects.