An Air Berlin flight from Namibia to Munich was delayed after police found a bag with a fuse in the luggage hall of the airport in the southern African nation's capital, German and Namibian authorities said Thursday.

Authorities in Windhoek, Namibia, were investigating whether the device found Wednesday morning could have exploded. But Air Berlin spokeswoman Sabine Teller said no explosives were found in the bag.

A scan showed batteries attached by wires to a fuse and a clock, Germany's Federal Criminal Police Office said, adding that German experts were being sent from South Africa to help with the investigation.

The incident came as Germany already was on edge after German Interior Minister Thomas de Maiziere raised the country's terrorist threat level on Wednesday, saying intelligence services had received a tip from an unspecified country about a suspected attack planned for the end of November.

Concern about the possibility of international flights being targeted by terrorists rose last month when two mail bombs were discovered while being sent on cargo planes from Yemen to the U.S. One of them went through a German airport before being found in Britain.

The suitcase was found in the luggage hall area near where those intended for the Air Berlin flight were, and the Air Berlin flight's luggage was rechecked as a precaution. All passengers on the flight had to identify their bags, and none was found without an owner, she said.

Still, de Maiziere told reporters that, according to preliminary investigations, it appeared likely the bag was intended for the flight.

"A lot speaks for the idea that the piece of luggage was supposed to be transported on a plane that was to fly to Munich," he said in Hamburg. He declined further comment, other than to say that the incident proved that "the checks worked."

Teller said she did not know whether Namibian police had determined the suspicious bag's owner, or what flight it was intended for.

Namibian police refused to provide any details of the investigation.

"There was a suspicious package found in the airport," said Chief Inspector Angula Amulungu. "Police are now investigating the package."

The Namibia Airports Company indicated in a statement that the bag may have been intended as cargo on the plane.

The airport operator in Namibia confirmed that a "suspicious parcel" had been discovered, causing the delay of the Air Berlin flight, but that once security authorities had "satisfied themselves with the safety and security of passengers and their baggage" it was allowed to continue.

"However, without its cargo which remained behind, also for further investigation," the agency said.

"The NAC cannot confirm the circumstances around this suspicious parcel, but such information will be availed once the Namibian Police have concluded their investigation," it said.

The plane arrived safely with all passengers in Munich early Thursday morning, Teller said.


Geir Moulson in Berlin and Jenny Gross in Johannesburg contributed to this report.