Members of the Pashtun Tahafuz Movement (PTM) representing ethnic Pashtuns protested in major cities across the region late on May 27, chanting slogans against the army and demanding the release of their leaders.

At least four PTM activists were killed and almost 50 were wounded on May 26 in North Waziristan, a region near the Afghan border, when soldiers opened fire on a protest staged by the group near a checkpoint outside the town of Boyya.

The Pakistani military said a group led by two PTM activists and lawmakers -- Mohsin Dawar and Ali Wazir -- "assaulted" the checkpoint.

However, videos of the May 26 protests posted on social media showed the demonstrators were unarmed when soldiers opened fire on them. Wazir was later arrested.

The protests were held at night because of the Muslim holy month of Ramadan, when people fast from dawn to dusk.

The army has allegedly barred Pakistani television channels from covering the rallies, which were nevertheless livestreamed and shown on social media.

The PTM emerged last year after an ethnic Pashtun was killed by a rogue police officer in the port city of Karachi.

With reporting by dpa and Dawn