Two French nationals who were kidnapped by Yemeni armed tribesmen were released on Sunday, the Yemeni Interior Ministry said in a statement.
The two people working with Doctors Without Borders were snatched from their car at gunpoint while travelling on Saturday during a mission in the northern province of Amran, the ministry said.
"Soldiers were sent to the mountainous area of Raida district of Amran and managed to free the hostages on Sunday," it said, adding that a security operation is underway to chase the kidnappers.
However, the ministry did not tell if the hostages were unharmed.
Foreigners are frequently kidnapped in Yemen by al-Qaida militants or tribesmen who asked for ransoms for the release of their jailed fellows. Most of the kidnapped have been freed unharmed.
On Saturday, Yemeni officials said a Dutch couple working in Sanaa were kidnapped a week ago by an unknown group.
Some officials believed that the Dutch couple and two South Africans who were abducted in Yemen's central province of Taiz last month were all at the hands of al-Qaida militants.
A Finnish couple and an Austrian man kidnapped by al-Qaida militants in Yemen last December were released in May.
However, the Yemen-based al-Qaida wing, the most active terrorist network in the Middle East, is still holding a Saudi diplomat.