In the shadow of a demolished mosque, three dozen men gathered in a house in a gloomy district of northern Belgrade. The Muslim call to prayer drifted out through the open door. The house Ð and the ruins it stands next to Ð represent just some of the ad hoc efforts of around 20,000 Muslims in the Serbian capital to worship in a city which is overwhelmingly Orthodox Christian. Belgrade has one mosque Ð dating from 1575 when the city was part of the Ottoman Turkish empire Ð and it has a fraught relationship with Islam. Many Muslims left during the collapse of socialist Yugoslavia, when Serbia backed its ethnic kin in Bosnia in the massacre of Muslim Bosniaks and fought a counter-insurgency war in its own southern province of Kosovo against mainly Muslim Albanians. The Islamic community in Serbia says Belgrade authorities have repeatedly ignored requests for new mosques to be built and says the shortage raises questions about the country's commitment to minority rights, an important gauge of its readiness for membership of the European Union. REUTERS/Marko Djurica SEARCH "DJURICA MOSQUE" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY. Matching text: SERBIA-ISLAM/MOSQUES