Indian authorities mounted a sweeping security crackdown across New Delhi on Saturday, detaining thousands of protesters as the country’s youth-led "Cockroach” movement sought to escalate a nationwide campaign against a contentious revision of voter lists.

The dispute has fueled anger at Prime Minister Narendra Modi’s Hindu nationalist government and election authorities.

Police intercepted demonstrators before they could reach Jantar Mantar, the designated protest site in the heart of the capital.

Officers chased away some protesters and detained many others, with several dragged away and bundled into police vehicles before being taken to temporary detention centers.

Several leaders of the "Cockroach” movement were also detained before reaching the venue, severely disrupting the planned demonstration before it could begin.

The security operation extended well beyond the protest site, with police setting up checkpoints on roads leading into the capital.

Officers stopped buses, cars and other vehicles and searched them for demonstrators as authorities moved to prevent protesters from gathering in the city.

Jantar Mantar was barricaded, while anti-riot vehicles equipped with tear gas launchers were stationed along key routes. Restrictions on mobile internet access and movement in parts of the city added to the hurdles facing protesters.

Police said Friday they had denied permission for the protest because the request was submitted late.

The scale of the crackdown underscored the authorities’ determination to disrupt a fast-growing protest campaign that has mobilized thousands of young people, drawn opposition support and intensified scrutiny of Modi.

The protests also come at a politically sensitive time, months after demonstrations led by the "Cockroach” movement over exam paper leaks forced Modi’s education minister to resign in July.

Movement leaders Abhijeet Dipke, Saurav Das and Ashutosh Ranka, who were expected to be at the forefront of Saturday’s protest, were detained after arriving at Delhi airport from Mumbai.

A video shared by the "Cockroach Janta Party” on X showed police boarding the aircraft and detaining the three men.

"The preplanned interception by Delhi police aims to cripple the leadership of today’s peaceful demonstrations before they even reach the protest site,” the movement said in a statement.

Loudspeakers around the protest site warned that gatherings of five or more people were banned in parts of New Delhi as authorities imposed sweeping security restrictions rarely seen in the capital. Journalists also faced restrictions in some areas.

Some protesters nevertheless broke through police cordons, chanting slogans against Modi and election authorities before being detained.

"We are a democracy, yet peaceful protests are being crushed by force. Shouldn’t we fight for our rights?” said Tanya Negi, a college student who traveled from Mumbai with two friends and arrived early Saturday. "Why is Modi afraid of India’s young people?”

The crackdown drew criticism from opposition leaders, who accused the government of curbing dissent.

"Is there a democracy in this country? A total siege over the city. Citizens are being driven out,” opposition lawmaker John Brittas told The Associated Press.

The protests center on the Election Commission of India’s Special Intensive Revision, which the opposition says has disenfranchised millions of eligible voters.

Protesters are demanding the resignation of Chief Election Commissioner Gyanesh Kumar and an end to the revision, which has removed more than 130 million names from voter lists so far.

The Election Commission and the government reject allegations of voter manipulation, saying the revision is intended to eliminate duplicate and ineligible entries.

The dispute has become a rallying point for opposition parties seeking to challenge Modi’s Hindu nationalist Bharatiya Janata Party.

Saturday’s planned demonstration followed days of protests in the capital, where opposition lawmakers also stepped up their campaign. Congress party leader Rahul Gandhi was briefly detained by police.

Gandhi and other opposition leaders have accused the commission of conducting the voter revision in a way that benefits Modi’s party. The opposition says voters more likely to support its parties have been disproportionately affected by the removals, while BJP supporters have been spared or added to the lists.

The commission and the government deny the allegations.

For the "Cockroach” movement, the voter list dispute offers an opportunity to broaden its campaign.

The movement began online in May and gained prominence through demonstrations, sit-ins and hunger strikes over alleged exam paper leaks. Those protests culminated in the resignation of Modi’s education minister in July, a rare political setback for a prime minister who has maintained a firm hold on national power for more than 12 years.

For Modi, the protests pose a challenge midway through his third term, though their political impact remains unclear. National elections are not due until 2029, but state elections next year in BJP-ruled Uttar Pradesh, India’s most populous state, and Gujarat, Modi’s home state, will test the party’s standing.