The authorities in Yemen say an American citizen who was taken hostage by tribesman two weeks ago in eastern Marib province has been released.

Officials in Sana'a said the man, Kenneth White, who worked for a United States oil services company, was handed over to mediators.

Reports said he was in good health.

Kidnapping of foreigners has become common in Yemen, and the authorities have introduced a law to make it a capital offence.

From the newsroom of the BBC World Service