Berlin ? A former German ambassador to the United States and four members of his family were reported missing and apparently kidnapped Wednesday while vacationing in a remote part of Yemen. It was the latest in a string of tourist abductions in the Arabian desert.

Juergen Chrobog, ambassador from 1995 to 2001, his wife and three adult sons were declared missing by the German Foreign Ministry. In Yemen, government officials said the family had been taken hostage by tribesmen who regularly seize Western tourists as bargaining chips in dealings with the government, according to wire reports from Sanaa, the capital.

Chrobog, 65, served as Germany’s deputy foreign minister until last month, when a new government came to power. In 2003, he played an instrumental role in winning the release of 14 European hostages – nine of them Germans – who had been kidnapped in the Sahara desert and held for six months by Islamic radicals.

Two Austrians and two Swiss were abducted in Yemen in the past two months. All were released unharmed a few days later.