Ukraine and pro-Russian rebels reached a cease-fire agreement on Friday, the first step toward ending fighting in eastern Ukraine that has caused the worst standoff between Moscow and the West since the Cold War ended.

The cease-fire deal was struck in the Belarusian capital, Minsk, along with a deal allowing for prisoner exchanges, deliveries of humanitarian aid and the withdrawal of heavy weapons after five months of conflict that has killed more than 2,600 people.

Despite some initial shelling in the rebel stronghold of Donetsk after the truce began at 6 p.m., the cease-fire appeared to be holding. But many residents and combatants were skeptical that the cease-fire could last long or provide the basis for a durable peace settlement. The two sides remain far apart on the future of the region.