Gaza, Nov 17 : The shelters managed by the United Nations Relief and Works Agency for Palestine Refugees (UNRWA) in central and southern Gaza are severely overcrowded with a record-high number of displaced persons. A UNRWA report has said that over 1.6 million people in Gaza have become internally displaced, including approximately 813,000 taking shelter in 154 UNRWA installations, Xinhua news agency reported. The United Nations Office for the Coordination of Humanitarian Affairs (OCHA) noted in its Wednesday report that the UNRWA shelters are accommodating far more people than their capacity allows, leading to the spread of diseases, including acute respiratory infections and diarrhoea, raising environmental and health concerns. The overcrowding is also affecting the agency's ability to provide effective and timely services, according to the OCHA. /IANS