The head of security at Chicago's airports has been fired, just weeks after a passenger was dragged from a United Airlines plane by security officers at O'Hare International Airport.

The Department of Aviation said in a statement Thursday that Jeffrey Redding "has been terminated from his duties" at O'Hare and Midway airports. No reason was given.

Redding wasn't immediately available for comment late Thursday.

Redding was overseeing the investigation into the forcible removal of 69-year-old physician David Dao from the United plane by three of his officers April 9. Dao has agreed an undisclosed settlement with the airline. Dao's lawyer said Thursday that the settlement averts any lawsuit against Chicago officials.

Separately, the Chicago Tribune recently reported that Redding was fired from his previous job for sexual harassment in 2015.