Vehicles travel through Pakistan's famous Khyber Pass en route to neighbouring Afghanistan. File picture: Muhammad Sajjad/AP

Islamabad - A son of Pakistani Taliban chief Mullah Fazlullah was killed with around two dozen other militants in a suspected US drone strike this week in Afghanistan, officials said on Thursday.

Abdullah, alias Iman Diri, was killed in Chawgam area in the eastern province of Kunar on Tuesday when a training camp for suicide bombers was hit by two missiles, Pakistani intelligence officials said.

At least 20 other would-be suicide bombers were also killed in one of the deadliest strikes against Pakistani Taliban hiding in Afghanistan's border region, they said.

Afghan authorities earlier said 27 militants were killed in the attack that targeted an Islamic seminary.

The latest strike is an indication that tensions between the US and Pakistan are melting after several difficult months. The relations between the two countries have been tense since US President Donald Trump accused Pakistan of providing safe heavens to Afghan militants.

Islamabad has also sought action by the US and Afghan forces against Pakistani militants, who allegedly crossed the border into Afghanistan to seek refuge after a series of offensives.

The son of Fazlullah is the fourth high-profile Taliban figure to be killed by drones within a month.

Last month, Pakistani Taliban deputy chief Khan Said Mehsud, alias Sajna, was killed by a drone, which was followed by the death of two other commanders.

"It is up to our expectations," one intelligence source said Thursday.

Taliban leaders often send their siblings to carry out suicide bombings. Last year, a 23-year-old son of Afghan Taliban chief Mullah Haibatullah Akhundzada died when he exploded his vehicle at an Afghan military base.