Croatia declared a state of emergency on Sunday in its central Kosinj valley after the Lika river flooded, cutting off road access to about 500 people and leaving some villages without electricity.
Mihael Kurtes, an official in the Perusic municipality, said the water level was rising by 5 centimetres per hour. State television reported that around 20 houses had been flooded, with others at risk.
Floods in central Croatia have been caused by melting of heavy snow which fell in late February and early March followed by heavy rain in recent days.
Mostly threatened by high water levels in the rivers are the central city of Karlovac and the towns of Jasenovac and Hrvatska Kostajnica where a landslide last week destroyed around a dozen houses. Fresh landslide is threatening near the town of Petrinja.
In neigbouring Montenegro, the Old Town of the coastal city of Budva was seen at risk of flooding after high winds and heavy rain over the weekend, while several villages in Ulcinj, near the Albanian border, were cut off by the rising Bojana river.