An international investigation was launched after a bizarre incident that took place on a United Airlines flight from Houston to Munich in June.

After a pilot realized he had live ammunition in his luggage, he took the ammunition out and threw it into the garbage, according to CNN. A passenger saw the ammunition and reported it to a flight attendant.

The captain then flushed the ammunition down the plane’s toilet.

When the plane landed, the pilot informed local authorities of the incident. German officials were able to retrieve the bullets from the plane.

Pilots are permitted to carry weapons under federal law, but only on domestic flights.

United released a statement acknowledging the incident and says the pilot remains an employee while the airline reviews the case.

It's been a tough week for United. A computer glitch caused a temporary flight stoppage earlier this week.