Harmeet Shah Singh, CNN
New Delhi (CNN) -- "Thousands of Indians took to the streets Wednesday in a show of solidarity with a 72-year-old activist arrested a day earlier as he prepared to go on a public hunger strike to push for stronger anti-corruption measures.
Authorities detained Anna Hazare on Tuesday for planning to hold the strike at a public park without agreeing to police conditions, investigators said.
Organizers did not accept six of 22 police conditions for allowing the protest, including limiting the crowd to the capacity of the ground, police said.
Police also briefly detained 1,300 supporters who planned to join Hazare at a protest site.
A magistrate sent Hazare and seven supporters to jail after they failed to post bail, according to Rajan Bhagat, a police spokesman in New Delhi.
They were freed hours later and shifted to a prison office after the magistrate issued release orders, jail spokesman Sunil Gupta said.
The group has refused to leave the prison office until they are allowed to hold their hunger strike without unacceptable conditions, the jail spokesman said.
Thousands gathered in several cities, chanting pro-Hazare slogans and echoing his demands.
Supporters carrying Indian flags held sit-ins, marches and noisy demonstrations. Many had "I am Anna" labels on their shirts.
Hazare conducted a similar five-day hunger strike in April at New Delhi's Jantar Mantar landmark, ending it after India's prime minister agreed to introduce long-pending legislation meant to crack down on graft.
Anti-corruption campaigners have rejected legislation prepared by the federal government to create a citizen ombudsman, saying the bill, now in Parliament, was too weak to tackle endemic graft in the system.
Critics, on their part, have accused the activists of undermining lawmakers who will decide the proposed law.
Prime Minister Manmohan Singh on Wednesday justified the arrests in a statement before parliament.
"Our Government acknowledges the right of citizens to hold peaceful protests," he said. "Shri Anna Hazare and his supporters would have been allowed to hold their protest fast if they had accepted the conditions under which the permission was granted and had undertaken to abide by the conditions. Since they declined to do so, Delhi Police was obliged to refuse permission to hold the protest fast."
Amid shouts by opposition lawmakers over the police response to Hazare's protest, the Indian prime minister also cited supremacy of the legislature.
"I am not aware of any constitutional philosophy or principle that allows any one to question the sole prerogative of parliament to make a law," he said.
Singh, whose government is roiled in massive corruption scandals, acknowledged in a national address earlier in the week that no single measure could handle chronic corruption.
"I believe that there is no single big step which we can take to eradicate corruption. In fact, we will have to act simultaneously on many fronts," Singh said.
Campaigners' insistence on not accepting legislation other than their own version of the anti-corruption bill was "beyond comprehension," Home Minister P. Chidambaram told reporters Tuesday.
"How can you indirectly endorse such an argument that it is his bill and no other bill (that is acceptable)?" the home minister said.
Police took Hazare into custody after the veteran activist told officers that he would "defy" orders not to hold a demonstration, the home minister said.
He said Hazare and his supporters were welcome to raise their concerns with a parliamentary committee that will scrutinize the legislation before it is presented to lawmakers for a vote.
Activists appealed to government employees to take a day off work in a show of solidarity with Hazare, a call federal officials were quick to term "wrong."
"I sincerely hope that the government servants don't respond to such wrong calls," the home minister said."