The area around the Carola Bridge has been cordoned off as bomb disposal specialists investigate the discovery, a police spokeswoman said.
Three women and seven men aged between 26 and 41 were injured.
The aide is charged with acting as an agent for a foreign secret service.
Passengers were set to face more disruptions on Friday due to strikes by aviation security staff at six German airports. Lufthansa is being hit particularly hard.
The order to vacate the area was because of the discovery of a World War II-era bomb, according to police.
