Described herein is a framework for collecting event related tweets. In accordance with one aspect of the framework, an initial set of keywords is constructed from a reference source. Tweets are collected from a messaging stream using the initial set of keywords for a first time window. The collected tweets are filtered to generate a candidate keywords set. The selected tweets of the candidate keywords set are grouped into a plurality of clusters. The clusters are classified into event related and non-event related clusters. The initial set of keywords is updated to obtain a new set of keywords.