Around 14,000 people in Lublin in eastern Poland have been evacuated after construction workers came across an unexploded bomb from World War II.
Residents have been asked to turn off gas, water and electricity, close doors and windows, and take identification and vital medications with them before being taken to the safety of schools and other large buildings.
The 250-kilogram bomb was found during work on building a new residential area. Previously there was an aircraft factory and an airport which may have been the intended target of the bomb.