A plane carrying 11 people, including a government minister, crashed into a lake Thursday near the Swiss border, and all aboard were feared dead, officials said.

The plane, a nine-seat Aerocommander AC-90 from Austria's Rhein-thalflug airline, was preparing to land at Altenrhein just over the border when it went down, said airline spokeswoman Renatte Moser."We have to fear that there are dead," she told The Associated Press.

A spokesman for the federal bureau for civil aviation said he feared there were no survivors.

Police and witnesses at the scene said dense fog hindered the search.

Moser said the nine passengers included Austria's social affairs minister, Alfred Dallinger, 62. There were two crew members on board.

A previously unknown group calling itself the Austrian People's Army claimed responsibility for the crash in a telephone call to the West German news agency DPA.

The Austria Press Agency said police were investigating the call. The caller did not say why the group would want to bring down the plane.

Rescue boats were on their way to the site of the crash in Lake Constance. The aviation official said a wheel and other wreckage had already been found in Switzerland.

Swiss police said the plane went down just inside Swiss territory, but the aviation official, who spoke on condition of anonymity, said the plane crashed into a part of the lake that is considered international territory.