Islamabad, Pakistan - Pakistani police have registered cases against a young ethnic Pashtun rights activist for criticising the country's powerful military during the latest in a series of rallies his organisation has held across the South Asian country.

Police registered cases in the western districts of Zhob and Qila Saifullah on Tuesday, accusing Manzoor Pashteen of "wantonly giving provocation with intent to cause [a] riot".

If convicted Pashteen, 26, faces a maximum of five years in prison.

Pashteen is one of a group of young men leading the Pashtun Tahaffuz Movement (PTM), which has organised rallies in solidarity with a Pashtun youth who was killed by the police.

The rights group gained prominence while leading a sit-in demanding justice for the extrajudicial killing of Naqeebullah Mehsud in the southern port city of Karachi in January.

Mehsud had been accused by police of being a Pakistan Taliban fighter, but an inquiry after his killing in a police 'encounter' found him innocent of any links to the group.

Rao Anwar, the senior police official held responsible for the youth's killing, went into hiding shortly after the inquiry, and remains wanted in the case.

"The registering of this case is extremely saddening, and we cannot condemn it strongly enough," said Alam Zeb Mehsud, a PTM leader.

"We have stood up for our rights. We have only spoken of what has happened to us - we have not lied, and we have never said anything unconstitutional."

Pashteen and Mehsud are among a number of young activists from the northwestern district of South Waziristan who have led a movement calling for the rights of ethnic Pashtuns to be respected.

They hold the state and military responsible for what they call the ethnic profiling of Pashtuns as "terrorists", and widespread rights violations in South Waziristan and elsewhere, including the collective punishment of civilians for attacks on security forces.

The Pakistani military denies any wrongdoing. In a statement to Al Jazeera issued in January, responding to the PTM's allegations, the military said while it investigated the possibility of locals facilitating attacks, it did so "strictly as per [tribal] traditions".

PTM leaders say they have been receiving threats from unidentified callers for years, since they first started organising their grassroots movement to protest alleged rights violations by the military.

"As time passed, we lost our fear. Now we are at a stage where if we get a call from the intelligence agencies, we don't care anymore. Because we have gotten used to it. They bother us on an almost daily basis," said Muhammad Idrees, 25, a founding member of the group.

Taking on the military

Direct criticism of the military, which has ruled the country for roughly half of its 70 years since independence, is rare in Pakistan.

Since May last year, the government has led a campaign targeting dissent against the military expressed on social media and on other online platforms.

"The PTM is not an engineered movement, it has been created by the situation," said Mehsud. "It has been created by a context of killings ... we have been the victims of terrorism, and then we are accused of being terrorists to boot. We have been facing this injustice for years."

PTM rallies held across the country since the Islamabad sit-in have attracted thousands of participants, although they have seen scant coverage in the country’s press.

At a recent rally, a local religious leader attempted to direct the young participants' anger towards the United States, signaling that armed groups such as the Pakistan Taliban were a US creation.

He was met by strident criticism, and forced to step off the stage, after the crowd loudly chanted an oft heard Pakistani leftist Urdu slogan: "This terrorism, it is backed by the military!"

PTM leader Mehsud denies his group is demanding "any kind of rebellion or anything against the State".

"We just want the protection of our life, our property and our honour.

"These three things, nothing else."

Asad Hashim is Al Jazeera’s Web Correspondent in Pakistan. He tweets @AsadHashim