We present the results of a search for 6.7-GHz methanol maser emission towards 241 colour-selected IRAS sources for which the flux density at 60 μm is less than 100 Jy. All the candidate sources meet the Wood & Churchwell criteria for ultracompact HII regions. Five new methanol maser sources are detected. We also present average distributions for the distances of the maser sources perpendicular to the Galactic plane, the maser luminosities, and the masses of the exciting stars obtained by using a statistical procedure to handle the ambiguity of kinematic distances. The mass distributions are used to obtain lower limits for the duration of the masing phase for masers associated with embedded stars with mass greater than 35 M_solar.