Wana Station House Officer Usman Khan confirmed Wazir had passed away after being shifted to Islamabad for treatment, reported Dawn News.

Police said an FIR in connection with the incident has been filed Wana police station.

According to another official, on Friday Arif Wazir was strolling outside his residence in Ghwa Khwa, near Wana, when armed persons opened fire from a moving vehicle, reported Dawn News.

He was initially admitted to District Headquarters Hospital, Wana, but was later shifted to an Islamabad hospital.

Rights group Amnesty International asked the country to carry out an independent investigation into the matter.

"The Pakistani authorities must carry out an independent and effective investigation into yesterday’s attack in South Waziristan on Arif Wazir, a member of the Pashtun Tahaffuz Movement. The suspected perpetrators must be held accountable," the group tweeted.

According to Zee News, the attack followed after he was arrested by Pakistani Police on April 17 for an alleged anti-Pakistan speech during his recent visit to Afghanistan. He was released on bail three days ago, it said.

Mohsin Dawar, a lawmaker of Pakistan's Parliament and member of the PTM, accused “state-sponsored terrorists” of carrying out the attack.

The PTM has been demanding an end of the extrajudicial killings and unlawful detentions of Pashtun people.

‘‘It is with the heavy heart I report that our comrade Arif Wazir has succumbed to his injuries. Wazir’s father and brother were killed by terrorists years ago. Our struggle against their masters will continue," said Mohin Dawar, a member of Pakistan’s parliament, according to Zee News.