A German Foreign Ministry spokesman confirmed that five members of one family, including a former deputy foreign minister, had disappeared in Yemen, adding that they were part of a group touring the country.
"A five-member family has gone missing in Yemen," spokesman Martin Jaeger told reporters.
The Yemeni official said the Germans were kidnapped during a trip to the eastern Shabwa province from the port city of Aden.
The kidnappers were reportedly seeking the release of jailed members of their tribe.
Juergen Chrobog, 65, who served as deputy foreign minister in the government of former Chancellor Gerhard Schroeder, which left office in November, is among the hostages.
Chrobog was Germany's ambassador to the United States from 1995 to 2001. In 2003, he was the top diplomat dealing with
Europeans abducted in the Sahara desert and was able to secure the release of 14 hostages, including nine Germans.
The kidnappers belonged to the al-Abdullah bin Dahha tribe, a number of whose members were arrested two months ago after a clash with another tribe.
The bin Dahha tribe has accused the government of favouring the second tribe.
The kidnapping is the third involving Westerners so far this year.
Last week, Yemeni tribesmen seized two Austrians. A month
ago, another group of tribesmen captured two Swiss tourists.
Both kidnappings were aimed at pressuring the government to free jailed relatives and all tourists were released unharmed.
Local tribesmen often abduct foreigners to press for their demands.