The sparring between India and Pakistan last month threatened to spiral out of control and only interventions by US officials, including NSA John Bolton, headed off a bigger conflict, five sources familiar with the events said, reported Reuters.

As per sources, India threatened to fire at least six missiles at Pakistan, and the latter said it would respond with strikes “three times over”, according to Western diplomats and Government sources in New Delhi, Islamabad and Washington.

A Government official, however, said India was not aware of any missile threat issued to Pakistan.

The exchanges did not get beyond threats, and there was no suggestion that the missiles involved were anything more than conventional weapons, but they created consternation in official circles in Washington, Beijing and London.

Reuters has pieced together the events that led to the most serious military crisis in South Asia since 2008, as well as the concerted diplomatic efforts to get both sides to back down. The simmering dispute erupted into conflict late last month when Indian and Pakistani warplanes engaged in a dogfight over Kashmir on Feb 27, a day after a raid by Indian jet fighters on JeM camps in Balakot in Pakistan.

That evening, Indian NSA Ajit Doval spoke over a secure line to the head of Pakistan’s ISI, Asim Munir, to tell him India was not going to back off its new campaign of “counter terrorism” even after IAF pilot Abhinandan’s capture, an Indian Government source and a Western diplomat with knowledge of the conversations told Reuters in New Delhi.

Doval told Munir that India’s fight was with the militant groups that freely operated from Pakistani soil and it was prepared to escalate, said the government source.

A Pakistani government minister and a Western diplomat in Islamabad separately confirmed a specific Indian threat to use six missiles on targets inside Pakistan. They did not specify who delivered the threat or who received it, but the minister said Indian and Pakistani intelligence agencies “were communicating with each other during the fight, and even now they are communicating with each other”.

Pakistan said it would counter any Indian missile attacks with many more launches of its own, the minister told Reuters, speaking on condition of anonymity.

“We said if you will fire one missile, we will fire three. Whatever India will do, we will respond three times to that,” the Pakistani minister said.

Doval’s office did not respond to a request for comment. India was not aware of any missile threat issued to Pakistan, a government official said in reply to a Reuters request for comment.