"Tribal negotiators gave the kidnappers a written pledge to work toward the release of the detained tribe members," the government official told Reuters. "It is unclear whether any of those whose release the kidnappers demanded are militants," he said.
Local officials had earlier said the men were held for their links to Al-Qaeda.
The man kidnapped — Dhafer Al-Shahrani — is a Saudi citizen who runs the Saudi-funded Al-Salam Hospital in the northern Yemeni province of Saada.
Kidnappings of foreigners and Yemenis are common in Yemen, where hostages are often used by tribesmen to press their demands on authorities.
In September, Al-Qaeda's regional Yemen-based wing, Al-Qaeda in the Arabian Peninsula (AQAP), claimed the kidnapping of a senior intelligence official in Saada and demanded the release of two imprisoned militants.
AQAP jumped to the forefront of global security concerns after it claimed responsibility for a foiled plot to mail two parcel bombs from Yemen to the United States last month.
