By Aftab Ahmed, Shivam Patel and Saurabh Sharma JAMMU, India/ISLAMABAD (Reuters) - 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.

India and Pakistan on Saturday reached an understanding to stop all military actions on land, in the air, and at the sea, in a US-brokered cease-fire to stop escalating hostilities between the two nuclear-armed rivals that threatened regional peace.

The frontier between arch-foes India and Pakistan was peaceful and had the "first calm night in recent days", the Indian army said Monday, after a surprise weekend ceasefire.