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.

India and Pakistan’s biggest skirmish in decades is also a major testing ground for Chinese and Western jets and other military hardware.

Beijing expresses ‘deep concern’ over escalation, with Donald Trump posting hours later about ‘full and immediate ceasefire’ mediated by US.