A senior member of the Hezb-i-Islami group in Afghanistan was shot dead in Pakistan's northwestern city of Peshawar, members of the group and police confirmed.

Haji Farid, the former spokesperson of Hezb-i-Islami leader Gulbuddin Hekmatyar, was killed on Tuesday by unknown gunmen as he left a mosque near his residence in the Tajabad suburb of Peshawar.

"He had just finished his fajr [morning] prayers and was leaving when two gunmen on their motorcycle fired shots at him that killed him on spot," Peshawar police spokesperson told Al Jazeera.

"We will conduct a post mortem and have launched an investigation into the murder incident."

Originally from Kunduz, Farid was based in Peshawar for the past decade with his family and actively supported Hekmatyar's return to Kabul in early May.

He was a family relative of Hekmatyar, whom he served during the Afghan civil war in the 1990s. The former leader stands accused of firing thousands of rockets into Kabul in the civil war.

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"We condemn the attack on Haji Farid and are deeply saddened by the news," Haroon Zakhailwal, a member of Hezb-i-Islami, told Al Jazeera.

Hekmatyar's return

Hekmatyar's arrival in the capital in early May came after his largely dormant group signed a peace deal with President Ashraf Ghani's government in September.

Following the 2001 US-led invasion of Afghanistan and fall of the Taliban, the US State Department designated him a "terrorist", accusing him of taking part in and supporting attacks by al-Qaeda and the Taliban.

But his Hezb-i-Islami armed group has been largely inactive in recent years, with its last big attack in Afghanistan, which killed 15 people - including five Americans - in 2013.

In February, the UN Security Council lifted sanctions on him, which paved the way for his return to Afghanistan.