The Pakistani military has killed more than 200 "Taliban and affiliated terrorists" in border clashes with Afghanistan, it has said in a statement.
It came after exchanges of fire between the forces of the two countries overnight in which Afghanistan claimed to have killed 58 Pakistani soldiers.
The Pakistani military said 23 of its soldiers had been killed.
Pakistan has closed border crossings with Afghanistan as a result, Pakistani officials said.
Afghan troops opened fire on Pakistani border posts late yesterday, with the country's ministry of defence saying this was in retaliation for Pakistani airstrikes in Afghanistan earlier in the week.
Pakistan said that it had responded with gun and artillery fire.
Afghanistan said it had killed 58 Pakistani soldiers, but gave no details on how it knew of the casualty figures.
It also said that 20 Afghan troops were killed or injured.
Pakistani security officials originally said they had inflicted casualties on Afghan forces but gave no number, reporting later that Pakistani forces had killed more than 200 Taliban fighters and affiliated militants.
Both nations claimed to have destroyed border posts of the other side.
Pakistani security officials shared video footage, which they said showed Afghan posts being hit.
The exchange of fire was mostly over this morning, Pakistani security officials said.
But in Pakistan's Kurram area, intermittent gunfire continued, according to local officials and residents.
Afghanistan's ministry of defence had previously said that their operation had finished at midnight local time.
Afghanistan said that it had halted attacks at the request of Qatar and Saudi Arabia.
The two Arab Gulf nations had released statements of concern about the clashes.
"There is no kind of threat in any part of Afghanistan's territory," the Taliban administration's spokesman, Zabihullah Mujahid, said.
"The Islamic Emirate and the people of Afghanistan will defend their land and remain resolute and committed in this defence."
Mr Mujahid said that fighting was ongoing in some areas.
Pakistan accuses the Taliban administration of harbouring militants who attack Pakistan, a charge that Afghanistan denies.
Two main border crossings closed
Pakistan's two main border crossings with Afghanistan, at Torkham and Chaman, were closed this morning, local officials said.
At least three minor crossings, at Kharlachi, Angoor Adda and Ghulam Khan, were also closed, local officials said.
There was no immediate comment from Kabul on the closing of the border. Landlocked Afghanistan has a 2,600km-long border with Pakistan.
The Pakistani airstrikes, not officially acknowledged by Islamabad, had targeted the leader of the Tehreek-e-Taliban Pakistan (TTP) militant group in Kabul on Thursday, according to a Pakistani security official. It is unclear if he survived.
The TTP has been fighting to overthrow the Islamabad government and replace it with a strict Islamic-led system of governance.
Mr Mujahid denied that TTP fighters were allowed to operate from Afghan soil.
