Pakistan and Afghanistan in dispute over checkpoint attack claims
Pakistan said its forces killed at least 50 Afghan troops and destroyed five checkpoints in clashes along a disputed border.
Afghanistan, however, dismissed the account, saying only two border police and a civilian were killed.
The two armies traded fire on Friday around the Chaman border crossing, which has been closed by Pakistan, stranding people on both sides.
The clashes, which ended after a few hours when local commanders contacted each other via an emergency hotline, marked a dangerous escalation between the two US allies.
The uneasy neighbours share a porous 1,375-mile border and have long traded allegations of supporting militant groups.
Pakistani Major General Nadeem Ahmad told reporters at the crossing that two Pakistani soldiers were killed in Friday's fighting and another nine were wounded.
He said around 100 Afghan forces were wounded.
Najib Danish, deputy spokesman for the Afghan Interior Ministry, said that account was "completely baseless".
He said two Afghan border police were killed in Spin Boldak, on the Afghan side of the border, and another 11 were wounded.
He said a woman was killed and 30 other civilians were wounded in the attack, which forced several local residents to flee their homes.
Pakistani officials said the fighting began after Afghan security forces fired on Pakistani census workers and the troops escorting them, killing nine civilians and wounding 42, including women and children.
They say the Afghan government had been notified and given the co-ordinates of the border villages, where the census workers were going door to door.
Afghan officials said Pakistani troops fired the first shots.
Afghanistan refuses to recognise the international border, which follows the so-called Durand Line, established more than a century ago when the British Empire controlled much of South Asia.
The line runs through the traditional homeland of the Pashtun ethnic group, which dominates Afghanistan and is a minority in Pakistan.
Afghanistan refuses to allow Pakistan to set up additional border posts, even though the frontier area is used by the Taliban and other Islamic militant groups.