The daughter of Afghanistan's ambassador to Pakistan was “severely tortured” after being kidnapped by unidentified assailants, officials said.
Silsila Alikhil, 26, was abducted as she was going home in Pakistan's capital Islamabad on Friday, said Afghanistan's foreign ministry.
“After being released from the kidnappers' captivity, Ms Alikhil is under medical care at the hospital,” it said.
The ministry said she was “severely tortured” during her ordeal and called for an investigation and protection for Afghan diplomats.
A hospital report on Saturday said Ms Alikhil had been treated for swelling on the brain and swelling and rope marks on her wrists and ankles.
Neighbours Pakistan and Afghanistan have long had a frosty relationship.
Kabul accuses Pakistan of allowing safe havens for Taliban insurgents, while Islamabad accuses Kabul of allowing militants to use its territory to carry out attacks in Pakistan. Both deny these charges.
A medical examination report, shared on social media and confirmed by the Pakistan Institute of Medical Sciences state hospital where Ms Alikhil was treated, said she was admitted with swelling and rope marks on the wrists and ankles.
The report said she was held for more than five hours and also noted she had some swelling in the rear occipital region of the brain.
Amid widespread consternation over the case in both nations, Afghan authorities summoned Pakistan's ambassador to Kabul to lodge a formal complaint.
Pakistan's foreign ministry said the Afghan embassy had informed it that Ms Alikhil was assaulted while riding in a rented vehicle. Police were investigating the “disturbing incident” and security had been tightened for the ambassador and his family, it said in a statement.
Pakistani Prime Minister Imran Khan wanted the matter treated as a top priority and the culprits caught within 48 hours, Interior Minister Sheikh Rashid Ahmed said.