Security agencies of central sounded an alert throughout Uttar Pradesh following intelligence input of terror strike  at places of large congregation.

Official sources said that the alert has been sent to all district administrations especially to Allahabad which will be hosting Magh Mela.

According to sources, the militants of banned Harkhat-ul Jehadi Islamia (HuJI) were planning to hit back following the arrest of five of its men in connection with the serial blast of November 23.