Uttar Pradesh Congress chief Ajay Kumar Lallu and several leaders were arrested following a clash between party workers and the police in Lucknow on Thursday.
Congress legislature party leader Aradhana Mishra was put under house arrest.
The Congress leaders were on their way to Raj Bhawan to submit a memorandum on the Pegasus spyware row when a clash broke out with the police.
Ajay Kumar Lallu was earlier in the day placed under house arrest by the police.
Lallu, however, joined Congress workers on foot as they took out a march from Parivartan Chowk to demand a judicial probe into the Pegasus spyware issue.
The police tried to stop Ajay Kumar Lallu but this led to a clash between party workers and the police.
The arrested party workers have been taken to Eco Garden.
Talking to reporters, the state Congress president hit out at the state government and also accused the centre of not respecting the privacy of people.
“The Congress will not back down from this struggle against the suppression of democracy,” he said.