Russia’s government has declared flooding in the Orenburg region a federal emergency, with preparations for possible flooding under way in three other regions. The floods, which were caused by rising water levels in the Ural River, forced more than 4,000 people including 885 children to evacuate, the regional government said. The state news agency Tass said a further 2,000 homes were flooded, bringing the total to nearly 6,300 in the region. The overall cost of the damage from the flood in the Orenburg region is estimated to about 21bn roubles (£180m), the regional government said on Sunday. Russia’s emergency situations minister, Alexander Kurenkov, arrived in Orsk – one of the hardest-hit cities – on Sunday to supervise rescue operations. “I propose classifying the situation in the Orenburg region as a federal emergency and establishing a federal level of response,” he said, according to RIA Novosti, a state news agency. The move means federal assistance and coordination can supplement state and local efforts. Orsk, which is about 12 miles (20km) north of the border with Kazakhstan, suffered the brunt of the floods, which caused a dam to break on Friday, according to its mayor, Vasily Kozupitsa. By Sunday morning, 4,500 residential buildings in the city of more than 200,000 people had been flooded and evacuation efforts were continuing, Tass said. A criminal investigation has been launched into suspected construction violations that may have caused the dam to break. Local authorities said the dam could withstand water levels up to 5.5 metres (18ft). On Saturday morning, the water level reached about 9.3 metres, Kozupitsa said. On Sunday, the level in Orsk reached 9.7 metres, according to Russia’s water level information site AllRivers. Authorities in Orsk reported that four people had died, but said the deaths were unrelated to the flooding. On Sunday, officials in the regional capital, also called Orenburg, about 150 miles from Orsk, wrote on Telegram that the situation in the city was getting worse, as water levels rose by 28cm (from the previous day. More than 1,300 homes flooded and 428 people were evacuated, they said. Footage from Orsk and Orenburg showed water covering the streets, dotted with one-story houses. The declaration of a federal emergency reflects the risk of flooding beyond the Orenburg region. Russia’s emergency situations ministry evacuated about 820 people in the neighbouring Samara region, the ministry’s regional directorate said. The Kremlin spokesperson, Dmitry Peskov, said on Sunday that Vladimir Putin had spoken to Kurenkov, as well as the heads of the Urals region of Kurgan and the Siberian region of Tyumen to discuss the situation and “the need … for early adoption of measures to assist people and their possible evacuation”. Preventive evacuation began on Sunday in two districts of the Kurgan region, the regional department of the emergency situations ministry wrote on Telegram. The Ural is 1,509 miles long and flows from the southern section of the Ural mountains into the north end of the Caspian Sea, through Russia and Kazakhstan.