Afghan authorities said on Friday they are ready for negotiations after Pakistan bombed their forces in major cities, emphasizing that “allies turned enemies are waging an open war,” Reuters reports.

Pakistan carried out strikes on Afghanistan’s capital, Kabul, the city of Kandahar—where leaders of the Taliban movement are based—and other cities, a Taliban spokesperson said.

The strikes marked the first direct attacks on the Afghan government following accusations of harboring militants seeking to overthrow the government in Islamabad.

Taliban spokesman Zabihullah Mujahid said there were civilian casualties on Friday but provided no further details.

Sources in Pakistan’s security services said the strikes were conducted using air-to-surface missiles targeting military facilities and Taliban posts in response to Afghan attacks on Thursday.

The clashes followed Pakistani airstrikes on Afghan territory last weekend, which triggered retaliatory attacks by Afghans along the border on Thursday, escalating long-simmering tensions over Pakistan’s claim that Afghanistan harbors Pakistani Taliban militants. Afghanistan denies the allegation.