In the past two weeks, three influential Pakistani militants based in Afghanistan have been assassinated, whilst another Pakistani militant group has been targeted in a deadly raid by Afghan special forces.
The apparent crackdown comes as negotiations between US and Afghan Taliban officials, aimed at bringing an end to the 18-year-long conflict, appear to be leading towards an agreement.
One militant source told the BBC he believed the deaths were the result of a secret pact between American and Pakistani forces. Pakistan is believed to have played an important role in facilitating the discussions.
In the latest incident, Shehryar Mehsud, leader of a breakaway faction of the Pakistani Taliban, was killed in the eastern province of Kunar when a remote control bomb exploded close to his home.
He had numerous rivals within militant circles, but they have denied involvement in his death, whilst members of his group told the BBC they believed Pakistani intelligence services were responsible.
The Pakistani Taliban and Afghan Taliban are separate organisations - focussed on carrying out attacks only within their own countries.
Various factions of the Pakistani Taliban established bases in eastern Afghanistan, following military operations against them in Pakistan.
It is alleged that the Afghan security services developed links to some of the groups - to counteract Pakistani support for the Afghan Taliban, which has been waging a long-running insurgency aimed at forcing out the Afghan government, backed by US-led forces.
Both countries officially deny supporting militant groups.
Earlier this month, two senior Pakistani Taliban commanders were killed in mysterious circumstances in the Afghan capital Kabul.
Meanwhile, on Monday reports emerged of a raid on the Hizbul Ahrar Pakistani militant group by Afghan forces in the eastern province of Nangarhar.
Members of Hizbul Ahrar were shocked at the raid, saying they previously believed they would not be targeted by Afghan security forces, as they have not carried out attacks within Afghanistan.
'Game rules' seem to be changing
The confusion in Pakistani militant circles comes as a high-profile former Pakistani Taliban spokesman appears to have escaped from the custody of Pakistan's intelligence services.
Ehsanullah Ehsan, who had claimed some of the groups most notorious attacks, including the shooting of schoolgirl Malala Yousafzai, surrendered in 2017. However, he was never presented in court, nor charged with an offence.
An audio message, purporting to be from Ehsanullah Ehsan was released last week, claiming that he had escaped, because Pakistani authorities had not been faithful to the terms of "a deal" he had made with them.
He later told reporters he had arrived in Turkey, but has so far refused to give further details, or video proof of where he is.
Many in Pakistan are sceptical that Ehsanullah Ehsan could have actually "escaped", suggesting instead he was released as part of an opaque deal.
There has been no comment from the Pakistani military or government as to what happened.
However, journalists have reported being directed to broadcast claims, attributed to "sources", that Ehsanullah Ehsan had provided "top level information" to the security services that led to successful operations against other militants.
Members of militant groups often refer to "games" being played by regional security forces. The rules of those "games" seem to be changing.