The supreme leader of Taliban group Mullah Haibatullah Akhundzada was the primary target of the explosion in Quetta city which killed four people including the younger brother of the Taliban leader.
The IHS Janes media outlet, quoting the local media reports reported that Mullah Haibatullah Akhundzada was also scheduled to be at the mosque.
No individual or group has so far claimed responsibility for the attack.
However, unconfirmed reports indicate the Taliban militants shot dead an Islamic State-associatd cleric on 17th of August following the assassination attempt.
The explosion took place at a mosque in Kuchalk area in the outskirts of Quetta city, the provincial capital of Balochistan province of Pakistan.
The explosion killed four people including Hafiz Ahmadullah, the younger brother of Mullah Haibatullah.
The Pakistani police officials confirmed last week that the explosion also wounded more than 20 other people.