UN officials say they are in close contact with the authorities in Yemen to secure the safe release of their staffers.
Five United Nations staff have been abducted in southern Yemen while returning to Aden after a field mission.
The staff were abducted on Friday in Abyan governorate, Russell Geekie, a spokesperson for the top UN official in Yemen, said on Sunday.
"The United Nations is in close contact with the authorities to secure their release," Geekie said.
Yemen's internationally recognised government, which is based in south Yemen, was working to safely free the UN staff abducted by unknown gunmen, the official news agency on Saturday cited a cabinet statement as saying.
An official at the UN office in Aden told Reuters that four of those seized were Yemeni nationals.
Yemen has been mired in violence since the Iran-aligned Houthi movement ousted the government from the capital, Sanaa, in late 2014, prompting a military coalition led by Saudi Arabia to intervene months later.
Among Yemen's many destabilising forces are terrorist groups Al Qaeda and Daesh that have in the past carried out attacks including in the south, which last year saw protests over deteriorating economic conditions.
The war has killed tens of thousands of people and caused a dire humanitarian crisis with 80 percent of Yemen's population reliant on aid.
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