ISLAMABAD (AP) — The United Nations on Thursday urged Pakistan and Afghanistan to bring “a lasting end to hostilities” to protect civilians, after days of fighting killed dozens of people in both countries and injured hundreds more.

It’s the deadliest crisis between the neighbors since 2021, when the Taliban seized power in Afghanistan following the collapse of the Western-backed government.

Cross-border violence has escalated since Oct. 10, with each country saying they were retaliating to armed provocations from the other. On Wednesday, the two sides agreed to a ceasefire.

The truce followed appeals from major regional powers, as the violence threatened to destabilize a region where groups, including the Islamic State and al-Qaida, are trying to resurface. There were no reports of overnight fighting. Key border crossings remained closed on Thursday.

The U.N. Assistance Mission in Afghanistan welcomed the ceasefire and said it was still assessing the number of casualties. It said the heaviest toll was in the south on Wednesday.

“Current information indicates that at least 17 civilians were killed and 346 were injured in Spin Boldak on the Afghan side of the border,” the U.N. mission said.

It said it had also documented at least 16 civilian casualties in several Afghan provinces during earlier clashes between the two countries.

“UNAMA calls on all parties to bring a lasting end to hostilities to protect civilians and prevent further loss of life,” the mission added.

Pakistan has not provided figures for civilian casualties suffered on its side of the border.

It has repeatedly accused Afghanistan of harboring militants, a charge rejected by the Taliban. Pakistan is grappling with attacks that have increased since 2021.

The two countries share a 2,611-kilometer (1,622-mile) long border known as the Durand Line, which Afghanistan has never recognized.