Some Orissa ministers are believed to have decided to keep away from the Republic Day celebrations in their home districts fearing attacks by Naxalites.
The phenomenon is restricted to the state's southern districts, where Naxalite groups hold sway.
Senior government officials are expected to hoist the national flag and attend other functions organised as part of the Republic Day celebrations in Raigada, Malkangiri, Gajapati and Nabrangpur districts.
An alert has been sounded in all southern districts and security has been tightened at all sensitive police stations areas, state Director General of Police N C Padhi told rediff.com in Bhubaneswar.
Of late, Naxalites of the People's War group have been very active on the Orissa-Andhra Pradesh border and carried out some violent attacks, including on police stations.
After declaring a large area, which encompasses parts of Orissa and Andhra Pradesh, as a liberated zone, the Naxalites are attacking the police and landlords in the area.
They have killed at least six politicians of the ruling Biju Janata Dal and Bharatiya Janata Party combine over the past few months, besides blowing up the house of a state minister, Arabinda Dhali.