The children's charity UNICEF has announced that its employee James Massaquoi, who was abducted in Yemen last year, has been released.

A statement by the UN agency said that the engineer, who is from Sierra Leone, was safe and healthy.

Massaquoi is a water engineer who had been working in Yemen to help provide water and sanitation services in order to improve the health of local children, the statement said.

He was abducted by unknown gunmen on October 6, 2013.

"We thank all those who have supported efforts to bring about his safe release and we ask that he now be allowed privacy as he enjoys his reunion with his family," UNICEF said.

Kidnapping incidents represent a serious challenge to the operations of international agencies in Yemen, limiting the mobility of aid workers and the progress of agency programmes.

Source: Al Jazeera