Leipzig/Halle Airport in eastern Germany suspended flights overnight after an unidentified flying object was spotted and a suspicious item was found, police said on Wednesday.
Several aircraft, including a passenger plane, were diverted during what police described as a "security-related incident."
The northern section of the airport resumed operations early in the morning, while the southern runway remained closed as investigations continued.
The suspicious item was found near the southern runway and examined by police, who deployed a bomb disposal robot.
Police were investigating whether the unidentified object and the suspicious item were connected.
There was no immediate danger, a police spokesman said.