India and Pakistan agreed to an immediate ceasefire on Saturday, unexpectedly halting the worst fighting in decades between the nuclear-armed neighbors, just when their tit-for-tat strikes appeared to be spiraling out of control.

After four days of escalating clashes, culminating in missile strikes on each others’ airbases, the nuclear-armed neighbours agreed to a ceasefire on May 10th. But within a few hours, India said its forces had responded to repeated Pakistani violations.