A suspicious piece of luggage that was about to be loaded onto a flight in Namibia was a “test device” from a U.S. company that tests alarm and security systems, Germany’s Interior Minister Thomas de Maiziere said in a news conference Friday in Hamburg, Germany.

An official with the U.S. Transporation Security Administration said Friday that they are working with German and Namibian authorities to determine the origin of the device and the reason it was being transported on the plane.

“We applaud the vigilance of the aviation security authorities who discovered the device and took quick action to ensure that it did not pose a threat to the aircraft and passengers,” the TSA official told CNN.

The discovery of the bag at Windhoek Hosea Kutako International Airport in Namibia delayed flight 7377 to Munich, Germany on Wednesday and raised security concerns, a spokeswoman for the airline, Air Berlin, said Thursday.

De Maiziere said he believed the device was from a U.S.-based company, but did not know which company. He said no one was warned in advance about the test device. The bag contained a functioning electronic clock with wiring attached, but no explosives.

“Air Berlin has confirmed that there was no explosive material in the laptop bag found in Namibia,” Sabina Teller, spokeswoman for Air Berlin, told CNN. “The luggage was found in the airport, at no point was on the plane. It had no luggage label so it was impossible to know where it was going, which company it was supposed to fly with or who it belonged to,” Teller said

De Maizere said authorities are investigating the bag’s origin and its intended destination.

After the bag was discovered, the flight’s 296 passengers and all bags were subjected to additional security checks. The plane later landed safely in Munich after a six- or seven-hour delay, said Air Berlin spokeswoman Silke Manitz.

Germany raised its threat level on Wednesday, saying concrete evidence had emerged of a possible attack planned in Germany later this month, It said there was evidence of persistent efforts by Islamists to launch an attack. A senior German counterterrorism source told CNN on Thursday that the German Interior Ministry warning was linked to recent threats to the country from al Qaeda in Pakistan.

Interior Minister de Maiziere addressed the threat level Friday by reiterating that people should go about their lives as usual.

(Source: CNN)