Pakistan has bombed areas in Afghanistan on Friday, after the Afghan Taliban earlier announced a major offensive against Pakistani military posts near the border.
It is the latest escalation of tensions between the neighbouring countries.
Afghanistan's Taliban government said it had launched an offensive on Pakistani military bases near the border on Thursday night.
Pakistan responded within hours, bombing targets in the Afghan capital, Kabul, and the provinces of Kandahar and Paktika - Afghan provinces close to its 2,600 km (1,615 miles) border.
Details are still emerging and the BBC has yet to confirm whether there are casualties on either side.
The bombings are the most significant development in the ongoing tensions between the two countries, which had agreed to a ceasefire last October following a week of deadly clashes.
Here is what we know so far.
What happened overnight?
Details are still emerging, and the BBC has not yet managed to verify all the claims.
The first reports began to surface on Thursday, 26 February.
An offensive was launched at 20:00 local time (15:30 GMT) along the border in the provinces of Nangarhar, Nuristan, Kunar, Khost, Paktia and Paktika, according to statements from Taliban officials.
Pakistan quickly retaliated, saying the Taliban had "miscalculated and opened unprovoked fire on multiple locations" across the border in its north-western province of Khyber Pakhtunkhwa, which had been met with an "immediate and effective response" by Islamabad's security forces.
It then launched a series of bombing raids on Afghanistan in the early hours of Friday morning, striking targets in Kabul and in border provinces.
Further outbreaks of violence were reported near the key Torkham border crossing, which sits between Peshawar and Jalalabad, by AFP journalists at the scene.
Zabihullah Mujahid, the Afghan Taliban spokesman, published - then subsequently deleted - a post on X that the group had launched strikes early on Friday on Pakistani military positions in Kandahar and Helmand, two provinces in Afghanistan.
The Afghan Taliban has said it carried out air strikes on several targets within Pakistan on Friday morning. Sources in the Taliban government told the BBC these were with drones launched from Afghanistan.
Pakistan's Minister for Information Atta Tarar said Pakistan had thwarted small drone attacks on Abbottabad, Swabi and Nowshera.