VENLO, The Netherlands, July 16 (Reuters) - Thousands of people fled their homes in the southern Netherlands on Friday as rising waters swamped cities and broke through a dyke. Prime Minister Mark Rutte declared a national disaster in the southern province of Limburg, which is sandwiched between badly flooded areas in western Germany and Belgium. read more Authorities started evacuating large parts of the city of Venlo on Friday afternoon, and earier told people in the smaller municipality of Meerssen to leave their properties. "There is a large hole in the dyke ... Immediately leave your home and get to safety," emergency services in Meerssen said in an online alert. Families were told to turn off their electricity and gas supplies. Much of the Netherlands is below sea level, protected by a complex system of ancient dykes and modern cement barriers that hold back water from the sea and rivers. The military later managed to reinforce the dyke near Meerssen, the regional security body told L1 radio, but the evacuation order remained in place. Soldiers worked frantically to enforce a dyke protecting the nearby village of Wessem from the rising waters of the Meuse river. "It"s frightening ... I’ve never seen the water come this high," 69-year-old resident Ton Linssen told Reuters. In Valkenburg, close to the Belgian and German border, floods engulfed the town centre, damaging many houses and other properrties and destroying at least one bridge. Water levels on the Meuse and the Rur had already reached record levels on Thursday, surpassing those that led to large floods in 1993 and 1995, local authorities said. There were no reported casualties.