MUNICH — At least one gunman opened fire near a shopping mall in Munich just before 6 p.m. on Friday, killing eight people and wounding scores of others in an assault that the German police said they were treating as a suspected terrorist attack.

The manhunt shut down traffic and public transportation across Munich, Germany’s third-most-populous city and the capital of the state of Bavaria. Police said they had found the body of a ninth person near the mall and were investigating the possibility that he was an attacker.

A state of emergency was declared in the city, plunging much of the metropolis into a desolate and fearful state of lockdown. As the transit system was shut down, commuters held their hands up in the air as they walked past police officers.

“At this point, we believe there are three perpetrators, there are conflicting reports, but there are as many as three perpetrators on the run,” said Marcus da Gloria Martins, a spokesman for the Munich police. He said the suspects were armed with “long guns.”