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.

The ceasefire had been expected to bring a swift end to weeks of escalating clashes triggered by the mass shooting of tourists last month that India blames on Pakistan.

Pakistan's army said on Tuesday that more than 50 people were killed in last week's military clashes with India which ended in a ceasefire agreed by the nuclear-armed neighbours, restoring peace to their border.

In such a scenario, where Pakistan faces an existential threat, or believes that its territory is about to be overrun, it may decide to “go nuclear”—even at the risk of self-destruction. The latest test of this pattern arose in the aftermath of a terrorist attack in Indian-Administered Kashmir on April 22.

India says its strikes into Pakistan-controlled Kashmir and Pakistan on Wednesday killed more than 100 militants.

The military operations chiefs of India and Pakistan spoke by phone on Monday, the Indian army said, as New Delhi reopened airports and shares rose in both countries following a ceasefire that paused days of intense fighting last week.