Two people, including a 72-year-old man have drowned in Romania after torrential rains hit the region.
Several hundreds of people were forced to evacuate as floodwaters submerged villages in the southwest of the country. In some areas waters measured up to three metres.
Dozens of army troops were sent to help with rescue efforts and helicopters flew to flooded areas.
In Bulgaria, a 61-year-old woman died in the floods and another person was reported missing.
Scores of Bulgarian villages and parts of the city of Gabrovo were left without electricity and water after flooding destroyed some of the water and sewerage infrastructure.
In Switzerland a clean up operation was underway on Monday after days of severe flooding in several cantons.
The heavy rains overnight on Monday into Tuesday also caused landslides in some areas.