Abstract: A process for preparing a gas bubble sensitized explosive composition. The present process comprises preparing an explosive composition comprising a water-in-oil emulsion and mechanically entraining gas bubbles into the explosive composition. Low viscosity emulsion explosives are able to be sensitized by this process. There is a preference for wax free emulsions to be used. The process is applicable to emulsion explosives comprising ammonium nitrate particles. By providing a process for the mechanical entrainment of stable gas bubbles we allow explosive compositions to be sensitized on-site by readily available mixing means.