Guwahati, Jan 23 (IANS): A massive security alert was sounded across northeast India Sunday after separatist rebels announced a boycott of the Republic Day celebrations Jan 26, officials said.

"We have placed security forces on high alert to ensure that militants are not able to create violence ahead of the Republic Day celebrations," Assam Chief Minister Tarun Gogoi said.

Six frontline separatist groups in the region have called a boycott of the Republic Day and also a general strike from 1 a.m. to 5.30 p.m. Jan 26.

The call has been given by the United Liberation Front of Asom (ULFA), the National Democratic Front of Bodoland (NDFB), Manipur People's Liberation Front (MPLF) - comprising several major militant outfits in the state, the Kamatapur Liberation Organisation (KLO), National Liberation Front of Tripura (NLFT), and the Tripura People's Democratic Front (TPDF).

These groups are active in Assam, Manipur and Tripura.

The six rebel groups announced their boycott Sunday through a statement e-mailed to journalists.

"Let us not forget that under the Indian colonial occupation the future of the people of this region is doomed. We have to fight Indian colonial rule to regain our sovereignty and independence so that we can survive and exist with dignity," the rebel statement received by IANS said.

Militant groups in the northeast have for years boycotted national events to protest New Delhi's rule over the region, and have staged violent attacks in the run up to the celebrations to make their presence felt.

Thousands of army, police and paramilitary troopers are standing guard in the northeast to foil militant attacks.

Militant groups often target vital installations like road and rail bridges, oil installations, and security forces as part of their design.