KABUL, Afghanistan — In a sign of deep political tension within the Taliban, a collection of religious leaders in the group’s headquarters in Pakistan issued a letter of rebuke this month to the new insurgent leader over his bloody crackdown on dissenting commanders.

It was unclear whether the letter, a copy of which was obtained by The New York Times and confirmed in interviews with several Taliban commanders, would amount to more than a symbolic setback for the Taliban leader, Mullah Akhtar Mansour. He has aggressively consolidated power since he was named leader in July. Commanders say he has kept a grip on the group’s biggest sources of income, including the trafficking of opium.

The Taliban commanders and members of the group’s ruling council at the headquarters in Quetta, Pakistan, most of whom spoke on condition of anonymity to discuss internal negotiations, differed on how much weight was carried by the letter from the religious leaders. But they agreed that it reflected unease over infighting and deadly crackdowns ordered by Mullah Mansour, including the deployment of hundreds of fighters to kill a rival senior commander this month.

The letter continued an uncommonly public airing of internal Taliban power struggles since the revelation this summer that the group’s founder, Mullah Muhammad Omar, had been dead for at least two years. Still, though Afghan and Western officials have sought to portray the factional disputes as a sign of weakness for the Taliban, there has been little evidence of that on the battlefield this year, where the insurgents have made sweeping gains.