India’s opposition leader Rahul Gandhi was briefly detained by police on Tuesday during a march protesting against the Election Commission, demanding its chief resign and alleging wrongdoing during a revision of voter rolls.

An AFP reporter saw Gandhi, a leader of the Congress Party, standing on a police barricade and waving an Indian flag. Officers detained him briefly, along with other lawmakers, and then released them soon after.

Opposition parties began their march from parliament towards to the Election Commission of India (ECI), but were stopped by heavy police deployments. Some politicians sat down on the street to wait.

Protests began on Friday, demanding that commission chief Gyanesh Kumar step down.

Opposition politicians have accused the commission of acting at the behest of Prime Minister Narendra Modi’s Hindu nationalist Bharatiya Janata Party (BPJ).

The ECI has rejected allegations of wrongdoing, saying the revision process is aimed at ensuring the accuracy and integrity of electoral rolls.

Kumar has not commented publicly.

“Gyanesh, it’s done, bro,” placards read, as well as signs alleging electoral manipulation.

Parties opposing Prime Minister Narendra Modi and members of the popular ‘cockroach’ youth movement launched protests against Chief Election Commissioner Gyanesh Kumar appointed by Modi’s government after the Indian Express newspaper reported divisions in the poll body last month.

The protests mark a fresh political challenge to Modi, midway into his third term in office and just months after similar protests forced the resignation of his education minister over exam paper leaks.

The reported differences over the lists and voter registration procedures stoked concern about the commission’s neutrality.

Holding a large banner that said “Save Democracy”, lawmakers raised slogans against Modi and demanded that Kumar resign as they marched from parliament to the Election Commission of India headquarters in central Delhi.

“The election commission is a puppet in the hands of the government. We are fighting to save our democracy,” Mallikarjun Kharge, president of the main opposition Congress party, told reporters as the march began.

Hundreds of security personnel, including paramilitaries in fatigues, fanned out in the area, with barricades thrown up and several routes closed.

Television showed security personnel, some holding batons, outside the barricaded Election Commission office.

Congress and other parties allege that the revised voter lists benefit Modi and his party. Kumar has not commented on the issue, but the commission and Modi’s BJP denied the accusations.

Authorities advised against travel around planned protest areas and shut off some routes.

Tuesday’s event is the latest of a series of almost daily demonstrations by student organisations, political parties and the ‘cockroach’ movement, which began last week.

India’s Supreme Court agreed on Monday to hear legal arguments seeking its intervention in the accusations against the poll body’s voter drive, and the conduct of its chief.

If “there are decisions against the law … We will take care of it,” the court said at the hearing, after the petitioners alleged bias by the poll body.