A French-Tunisian staff member of the International Committee of the Red Cross (ICRC), who had been abducted here, was released on Monday night, a spokeswoman for the ICRC's Sanaa branch said in a statement.

"It is a happy day for the ICRC delegation in Yemen, as we have the pleasure to announce the release of our abducted staff member, Nourane Houas, after 10 months of abduction," Rima Kamal said.

"She has just arrived in Muscat, one hour before Monday midnight," Kamal said.

"Her release was the painstaking work of ICRC teams in Geneva, Sanaa and beyond. It has taken a lot of effort, inside and outside Yemen, and over many months," the spokeswoman said.

"We are grateful for the support and cooperation of all those who helped secure her release," she said, without giving further details or who was behind the kidnapping.

On Dec 1, 2015, Yemeni gunmen abducted Houas, while she was on her way to work in Sanaa, capital of Yemen.

The ICRC had halted all field movements in Yemen for days after the kidnapping, but then resumed its humanitarian activities.

Foreigners were frequently abducted in Yemen, a country that has seen turmoil since the 2011 political upheaval, against then President Ali Abdullah Saleh.

Militant groups kidnapped foreigners to ask for ransoms. But it is rare that aid group staff was kidnapped.

Security in the country has deteriorated since Mar, 2015, when war broke out, after dominant Shiite Houthi group, supported by former President, Saleh's loyalists, seized Sanaa and drove out the government of President Abd-Rabbu Mansour Hadi into exile.

More than 10,000 Yemenis have been killed in ground battles and Saudi-led coalition air strikes since then, half of them civilians.