MOSCOW (AP) — Authorities in the Russian city of Orenburg, near the border with Kazakhstan, on Friday announced a mass evacuation from there after water levels in the Ural River rose further, threatening the area with more flooding.

The Orenburg mayor, Sergei Salmin, called on the residents in a statement on the messaging app Telegram in the morning to “urgently evacuate” as sirens rang out in the city.

“This is not a drill,” Salmin wrote. “The flood situation in Orenburg is extremely dangerous. Over the past 10 hours, the water level in the Ural (River) has risen by 40 centimeters and is now at 11.43 (meters). These values are dangerous.”

Images from the city showed entire districts submerged in water.

The deluge hit the region, located some 1,200 kilometers (745 miles) southeast of the capital, Moscow, on the border with Kazakhstan, after a dam on the Ural River burst last week in the city of Orsk under the pressure of surging waters. The authorities have designated the situation in the region as an emergency of federal importance.