Eight people were arrested from the opposition Maldivian Democratic Party (MDP)'s Lootuvaifi Lootuvaifi (Stop the Looting) rally held on Friday night.
The main opposition party told reporters that detainees include parliamentarians and local island councillors.
The detainees also include former MP Yasir Abdul Latheef, former MP Yoosuf Abdulla and Maafushi council President Hassan Solah.
Police have not disclosed the identity of the detainees, but confirmed that eight people were in their custody.
MDP's legal team expressed concern as the police had been denying the detainees their right to a defense attorney.
"Police are denying them this right. We don't even know where they are being held," lawyer Ibrahim Shiyam told reporters outside the police station.
More than 2,500 people gathered in Male's Artificial Beach for the rally, which began at 9:00 pm on October 3. Organizers had planned to march through Male'.
After a few brief addresses and five demands to President Mohamed Muizzu, rally participants began marching through the main road in the capital city.
But police put up barricades on Majeedhee Magu and used pepper indiscriminately and without warning against the peaceful demonstrators.
They also used a sonic weapon to disperse the crowd despite the protest being centered in a densely populated prime residential area in Male'.
MDP officially ended the protest at 12:00 am. But some rally participants marched through Male' much later into the night.
Meanwhile, MDP's Vice President for Hulhumale' Central constituency, Mohamed Raslan suffered a heart attack because of a targeted pepper spray attack.
He is currently at Indira Gandhi Memorial Hospital (IGMH). MDP Chairperson Fayyaz Ismail said he was in critical condition.
