Fearing a repeat of Germany- and Belgium-type terror attacks on foreigners involving machetes and axes, the Centre has asked its central electronic and cyber monitoring agencies and cyber cells of state police forces to immediately step up surveillance of social media sites and electronic monitoring of phones in key areas.

The threat, which according to a senior intelligence official, is quite serious, emanated after the agencies electronically monitored surveillance of Manseed alias Omar al Hindi, the inspirator of Kerala-Tamil Nadu-based ISIS module for more than two weeks before he landed in India from Qatar on September 30.