India and Pakistan engaged in the most intense fighting in decades with four days of escalating conflict that included fighter jets, missiles and drones packed with explosives. It ended almost as abruptly as it began.

NEW DELHI — India and Pakistan agreed to an immediate ceasefire on Saturday, halting days of clashes that killed dozens of people and pushed the nuclear-armed neighbors to the brink of war.

Civilian airports were reopened and stocks jumped in both nations, signs of confidence that the agreement to halt the most alarming fighting in decades was holding.