Pakistan launched airstrikes on Thursday. It hit 10 sites in Afghanistan.

The sites were in Kandahar, Paktia and Khost provinces. Pakistan said the strikes were retaliation.

It claimed Afghanistan launched drone attacks a day earlier. One attack reportedly hit a Pakistani border post.

Pakistan blamed Afghanistan's Taliban government for the drone attacks. A Taliban government spokesman denied the claim.

He said Pakistan's strikes killed four civilians in Afghanistan. The civilians died in southern and eastern provinces.

The strikes followed earlier airstrikes on Monday. Pakistan said those strikes killed 28 militants.

But the United Nations said at least three civilians died. Four others were injured according to the United Nations and Afghan officials. The new strikes mark an escalation in fighting between Pakistan and Afghanistan.