Catholic Belarussian

It was in Easter week (in the gregorian style of calendar counting) and when we sneaked into this church at a central downtonwn square - opposite the university - some sort of service was still going on, with a procession of mainly women walking around the church up to different icons, singing. The women were also leading the procession and the singing - either in a catholic or orthodox tradition I would have thought that unusual. I would have guessed a catholic service to have been conducted in Polish but my husband claimed to my surprise they were singing in Belarussian. I learn something new everyday!