A firefighting robot is dousing an unexploded World War Two bomb with cold water in the German city of Dresden, to allow experts to defuse it.
The first attempt to defuse the 250kg (550-pound) bomb failed and caused a small explosion and fire on Wednesday after sparks ignited insulation material placed around it.
Police are maintaining a cordon around the site amid fears of an explosion.
British and American bombers devastated the eastern German city in the war.
The bomb was found on Tuesday during construction work at the intersection of two streets - Löbtauer and Werner - in central Dresden.
About 9,000 people who were living near the site have spent two nights in emergency accommodation. They include many elderly people evacuated from two care homes.
Many flights to and from Dresden airport have been cancelled because of the risk that the bomb could explode.
In February 1945 an estimated 25,000 people died in the British and American bombing of Dresden. It created a firestorm that left 33 sq km (12 sq miles) of the city in ruins.
Some of this weeks evacuees are old enough to remember the citys destruction in 1945.
The intense Allied air campaign against Nazi Germany left a legacy of thousands of unexploded bombs. Builders regularly unearth such bombs in German cities.
The northern city of Kiel is preparing to make a bomb safe on Friday - an operation that will involve evacuating about 4,300 residents.
Last month about 10,000 people were evacuated in central Berlin during a successful operation to defuse a British wartime bomb.