Pashtun Tahaffuz Movement (PTM) leader Manzoor Pashteen was arrested from Shaheen town in Peshawar in the early hours of Monday.
PTM is known for its strident criticism of the country's powerful military for alleged enforced disappearances and extrajudicial killings, according to Al Jazeera.
Along with Pashteen, the police also arrested nine other PTM workers who were identified as Muhammad Salam, Abdul Hameed, Idrees, Bilal, Mohib, Sajjadul Hassan, Aimal, Farooq, and Muhammad Salman.
"He was required in a case by the police from Dera Ismail Khan city police station, so we [arrested him]," police official Nabibul Khan was quoted as saying.
However, the police immediately did not provide further details on what charges the rights activist was arrested.
According to the police, a case was registered against the PTM chief at the City police station in Dera Ismail Khan on January 18 under sections 506 (punishment for criminal intimidation), 153-A (promoting enmity between different groups), 120-B (punishment of criminal conspiracy), 124 (sedition), and 123-A (condemning the creation of the country and advocating the abolishment of its sovereignty) of the Pakistan Penal Code, Dawn reported.
According to the FIR, a copy of which is available with the Pakistan newspaper, Pashteen and other PTM leaders had attended a gathering on Jan 18 in DI Khan where the PTM chief had allegedly said that the 1973 Constitution violated basic human rights.
The FIR added that Pashteen also made derogatory comments about the state.
Following Pashteen's arrest, #ReleaseManzoorPashteen started trending on Twitter with various politicians and human rights activists calling for his release.
( With inputs from ANI )