At least nine top United Liberation Front of Assam militants have sneaked into Assam for conducting subversive activities targeting oil refineries and other vital installations on November 27, which the ultras observe as 'Black Day'.
A posting in the Assam police website said the nine Ultras recently sneaked into the state from Myanmar, Bhutan and Nagaland to carry out blasts in protest against the first army operation against the outfit on that date in 1991.
Their main targets were oil refineries and other vital installations, it said.
The nine ULFA militants are Bosa Singh, Pinku Phukan, Upen Borgohain, Bimal Kalita, Sadin Rai, Rajanikanta Singh, Pulak Bharali, Hitesh Rai and Akon Moran.
Security has been tightened in and around the vital installations in view of the report.