At least one man was severely injured in a drone strike allegedly carried out by a US spy plane in Kurram Agency's Badshah Kot area near the Pak-Afghan border.
According to officials, the man severely injured in the strike was identified as Khalid, said to be an "Afghan extremist".
The missile fell close to a house in the area, eyewitnesses said.
In a similar strike carried out on the Afghan side, two "Afghan extremists" were killed in the Khost province of Afghanistan, said officials.
The two men were killed in the the strike carried out close to an extremist den in the Khani Kila area.
According to eyewitnesses, US spy drones have been circling the Pak-Afghan border since Wednesday morning.
On December 26, 2017 two people were killed in a drone strike which targeted a vehicle. The strike occurred in the Mata Sangar area of Kurram.
In the same month, last year, a US drone had fired a missile at a compound in the same area. The missile had been fired at the compound at around 9pm, but no casualty was reported.
In November 2017, three suspected militants were killed in another drone strike targeting a militant compound in Afghanistan's Paktia province near the Pak-Afghan border.
Drone strikes have surged in Kurram in the wake of US President Donald Trump’s announcement of a new Afghan policy in August, in which Pakistan was also accused of offering “safe havens to agents of chaos”.