"Nagaland is burning. Fair to ask what happened to the 'Naga Accord' (Prime Minister Narendra) Modi signed with great fanfare on live TV," the Marxist leader tweeted.
Expressing concerns over the situation in some northeastern states, Yechury accused the ruling Bharatiya Janata Party (BJP) of being focused on power grabbing.
"Besides Nagaland, Manipur troubled. Situation in Assam volatile. Security concerns in Arunachal Pradesh. And BJP focused solely on grabbing power."
Nagaland capital Kohima on Thursday witnessed violence as a mob went on the rampage, burning government properties and vandalising official vehicles in protest against Chief Minister TR Zeliang's refusal to meet their demand on local body polls.
The tribal bodies have been opposing the Naga People's Front government's decision to hold the elections with 33 per cent women reservation, saing it infringes on the special rights for Nagaland guaranteed by Article 371 (A) of the Constitution.