An intensive search operation is underway after three prisoners escaped from a high-security jail on the outskirts of Jammu city, in Indian-administered Jammu and Kashmir.

The jail was specially constructed to hold militants involved in the Kashmir separatist campaign of the past nine years.

Reports say it is believed that the three escapees cut through iron-bars and scaled a wall, but the authorities also suspect they may have been given some assistance.

Security forces have been put on maximum alert and a top-level enquiry has been ordered.

In the meantime 12 prison officials have been suspended and accused of neglecting their duty.

The authorities allege that the three escapees are Pakistanis. One of them is accused of being the mastermind behind a series of Republic Day blasts at a Jammu stadium in which eight people were killed and more than 60 injured, the governor escaping unhurt.

The other two escapees are also accused by the authorities of having been involved in serious incidents of violence.