The man leading protests accusing Pakistan’s army of human rights abuses has been arrested for alleged criminal conspiracy and sedition.
Manzoor Pashteen was taken into custody along with nine others from his Pashtun Protection Movement in Peshawar.
Mr Pashteen has drawn tens of thousands to rallies in cities around Pakistan.
A fellow protest leader said he was being punished for simply demanding human rights. The powerful military, unused to criticism, denies wrongdoing.
Mr Pashteen, who shot to prominence two years ago, has become the face of the Pashtun Tahaffuz (Protection) Movement (PTM), in a country where few openly challenge the military.
The non-violent protests began over the alleged extra-judicial killing of a young man of ethnic Pashtun heritage by police in Karachi.
The movement then expanded, demanding accountability from Pakistan’s army for alleged human rights abuses against Pashtuns committed during the war against Islamist extremists in the country’s north-west.
Pashtuns make up the majority of the population along the border with Afghanistan.
The protests, drawing at times tens of thousands of demonstrators, have rattled the military.
Manzoor Pashteen has been accused of “hate speech” and sedition among other offences.
He was taken into police custody in Peshawar but is expected to appear before a magistrate in Dera Ismail Khan, some 300km (186 miles) to the south.