Banned Harkat-ul-Jehadi Islamia (HuJI) is believed to be behind the serial blasts that rocked Uttar Pradesh, killing over a dozen people and injuring several others.
Sources in the security agencies said the terror strike could be seen as a revenge by the banned outfit for the assault on its members including the recent incident when lawyers manhandled three Jaish-e-Mohammed militants arrested in Lucknow last week.
They said Jaish could have sought the help of HuJI as both the outfits followed the Deoband sect of Islam.
HuJI, which is being mainly run from Bangaldesh, has managed to establish cells in the Uttar Pradesh and that the outfit was responsible for previous major terror attacks.
All three court premises in Lucknow, Faizabad and Varanasi, targeted today by the militants, had seen an incident of manhandling of militants or activists of anti-Ram temple in Ayodhya by lawyers.
Last week, three JeM militants were roughed up by lawyers and the bar association refused to take up their cases.
Faizabad court premises was witness to an altercation between activists of a Babri Masjid organisation and lawyers. The local bar association had banned its advocates from taking up their case.
The court premises in Varanasi was witness last year to beating of a Waliullah Khan, the main accused in the Sankat Mochan temple explosions.
In a related development, an outfit by the name of Al-Hind Mujahideen had claimed responsibility about the attacks and sent emails to some media houses.