SOFIA, Bulgaria - A dam in southern Bulgaria burst Monday after days of heavy rain, sending a 2.5-metre torrent surging through a village along the Greek border. The disaster brought the region's toll from flooding to eight dead, 10 missing.

The dam on the Ivanovo Reservoir collapsed, flooding 700 houses in the village of Bisser, civil defence chief Nikolai Nikolov said. Four bodies were found in the raging waters, three of them elderly men, the Bisser mayor reported.

A reporter at Bisser saw the muddy water crashing into homes, tossing cars, drowning animals and uprooting trees. Many homes were destroyed and some residents had to climb onto their roofs to escape.

Many in Bisser had to be rescued from their water-logged homes and were spending the night in emergency shelters. Officials were still assessing the damage late Monday.

Authorities have declared a state of emergency in much of southern Bulgaria due to the heavy rain. District governor Irena Uzunova said four others were killed and 10 people are still missing in the floods that have washed away bridges and roads.

Bulgaria's civil defence agency warned that two bigger dams at Ivaylovgrad and Studena were also on the brink of overflowing and residents were urged to prepare for an evacuation. The government also warned Turkey and Greece of floods surging down the Arda, Tundzha and Maritsa rivers.

Prime Minister Boiko Borisov and Interior Minister Tsvetan Tsvetanov came to the flooded region late Monday and pledged emergency aid.

Train services were suspended in southern Bulgaria and many roads remained closed, submerged under water or badly damaged.

Rain-soaked landslides also derailed the engine of an Istanbul-bound train near the border town of Svilengrad, causing no injuries but stranding passengers for hours.

In neighbouring Turkey, the state-run Anadolu Agency reported that due to flood warnings some businesses and villagers close to river banks near the Bulgarian border had started to evacuate. Authorities said only large trucks were being allowed to travel between Bulgaria and Turkey due to the flooding.