Two gunmen opened fire Tuesday in a hospital in India-occupied Kashmir where a militant was brought for treatment, escaping with the high-profile prisoner and killing two police officers.

A manhunt is underway after the attackers stormed the Shri Maharaja Hari Singh Hospital in Srinagar and opened fire on police guarding Naveed Jutt, a Pakistani rebel imprisoned since 2014.

One officer died at the scene while another later succumbed to his injuries in hospital, deputy inspector general of police Ghulam Hassan Bhat told AFP.

The trio escaped on a motorcycle and were still at large. Police have set up roadblocks and fanned out in search teams across Srinagar.

Jutt was second in command of the Lashkar-e-Taiba (LeT) militant group at the time of his arrest.

India accuses Pakistan of arming, training and deploying militant groups, including LeT, to foment unrest in the part of Kashmir controlled by New Delhi, where many support the rebel cause.

Islamabad denies the allegations, saying it only provides diplomatic and moral support to the Kashmiri struggle for self-determination.

Pakistan and India both control parts of Kashmir but claim the whole of the territory and have fought two of their three wars over it since independence in 1947.