What is the fine-grained topic of the following text: The Assam Government considers the recent arrest of ULFA cadres and linkman in Tinsukia and Dibrugarh districts in Upper Assam as “serious”, and their subsequent statements that they were on a mission to disrupt the I-Day celebration in the region. Only return the topic.
Arrest of ULFA cadres planning to disrupt I-Day celebration in Upper Assam