BERLIN — German police officers and firefighters went door to door on Friday in a one-mile area of downtown Berlin, telling workers and residents that they had to get out.

A 1,100-pound World War II-era bomb was found last Saturday, and it was time to remove it.

The 70-year-old bomb, which the Berlin police said had mostly likely been dropped by a British bomber during the war, was found during construction in the center of the German capital, just north of the main train station, government buildings and major tourist sites.

As many as 12,000 people were evacuated, and two schools nearby were opened to the public to provide shelter for people while bomb experts worked to defuse it.

“It’s part of life” said Norbert Benke, 61, who works in the affected area. “It’s still the impact of the Second World War.”