"Militant activities" refers to actions or behaviors that involve organized and aggressive actions to achieve certain goals and usually involve the use of force or violence. Full definition
I am a professor at Catholic University of Louvain and I am also engaged in militant activities including with the Amis du Monde Diplomatique (Friends of Le Monde Diplomatique monthly), as an organiser of the Forum of the Small Villages of the World and the «Groupe de Lisbonne»...» (religion-online.org)
The region has turned into a base for drug smuggling, weapons smuggling, human trafficking, and a wide array of militant activity. (blog.politics.ox.ac.uk)
The linking of Islamic education with militant activities against the West has resulted in the propagation of simplistic notions of Islam as a monolithic, ideological and violent faith (Saikh, 2006). (globaleducationmagazine.com)