Heavy rainfall has flooded thousands of homes in Bulgaria and caused rivers to rise to dangerous levels in neighbouring Greece and Turkey.
Floods have swept Bulgaria - here at Ihtiman, 50km east of Sofia
A state of emergency has been called in parts of Bulgaria and Greece with bridges damaged and farmland inundated.
The governor of Turkey's province of Edirne has accused Bulgaria of letting dangerous amounts of water through dams on the Arda river.
The floods are said to be the border region's worst in 15 years.
The most badly affected areas are those along the path of the Arda and Evros rivers. The Evros forms the border between Greece and Turkey.
Greek officials say the Arda has reached danger levels and both they and Turkish authorities fear the situation will get worse.
Three artificial lakes on the Arda inside Bulgaria overflowed for a second day, but Bulgarian officials insist people downstream are in no danger.
However, the governor of Turkey's Edirne province, Nusret Niroglu, called on his foreign ministry to lodge an official protest with Bulgaria over water released through dams.
A district of Edirne was flooded and the military were called in to rescue stranded residents.
A state of emergency has been declared in Greece's Evros region, where 75,000 acres (30,000 hectares) of land have been flooded.
Military personnel rescue stranded students in Edirne, north Turkey
The province's prefect told the Reuters news agency: "We are preparing for a nightmare... At the moment we are at the mercy of the army who have been told to be on standby to evacuate people."
One of the worst hit towns is Soufli, where 6,000 acres of fields have been flooded.
Soufli mayor Minas Stergiou said: "We have ordered people... not to approach the river, which is 500 metres from the town. Our only aim now is not to have any deaths."
Bulgaria has a state of emergency in 15 central and southern districts but the north has not been spared.
The Danube at Vidin in the north west rose a metre in 24 hours, forcing neighbourhoods to be evacuated.
Rail traffic between Sofia, the capital, and second city Plovdiv, where more than 400 homes were flooded, was disrupted.
Last summer, 26 people died in floods that cost Bulgaria about $600m (£343m; 500m euros).