HateNet-BN at BLP-2025 Task 1: A Hierarchical Attention Approach for Bangla Hate Speech Detection

AbstractThe rise of social media in Bangladesh has increased abusive and hateful content, which is difficult to detect due to the informal nature of Bangla and limited resources. The BLP 2025 shared task addressed this challenge with Subtask 1A (multi-label abuse categories) and Subtask 1B (target identification). We propose a parameter-efficient model using a frozen BanglaBERT backbone with hierarchical attention to capture token level importance across hidden layers. Context vectors are aggregated for classification, combining syntactic and semantic features. On Subtask 1A, our frozen model achieved a micro-F1 of 0.7178, surpassing the baseline of 0.7100, while the unfrozen variant scored 0.7149. Our submissions ranked 15th (Subtask 1A) and 12th (Subtask 1B), showing that layer-wise attention with a frozen backbone can effectively detect abusive Bangla text.