Two Spanish aid workers released in Somalia after spending 21 months in captivity are on their way home, their employer said in the Kenyan capital Nairobi on Friday.

Medecins Sans Frontieres (MSF) Program Manager for East Africa Will Robertson said the 42-year-old Montserrat Serra and 32-year- old Blanca Thiebaut flown on board a Spanish military plane are healthy and keen to see relatives in Spain later Friday.

"Mone and Blanca need some time to adjust to their freedom and the organization asks the media and the public to respect theirs and their families' need for privacy," Robertson told journalists in Nairobi.

He called on the media and the public to respect the privacy of the women and their families when the plane carrying them from Djibouti lands at the Spanish air-base of Torrejon (Madrid).

Robertson said the international medical charity is extremely relieved to confirm the release of the two colleagues, who were abducted from the refugee camps near Dadaab, Kenya on Oct. 13, 2011 and held in Somalia, before released on Thursday.

"MSF continues offering full support to Mone and Blanca as well as to their families," he said and thanked everyone for the support and solidarity shown to the families of the released aid workers.

"Once again, MSF strongly condemns the attack against these humanitarian aid workers who were providing medical assistance to the most vulnerable Somali population fleeing hunger and war in their country," Robertson said.

"The organization is also grateful to the media for their understanding regarding the sensitive nature of communicating on the abduction and for their consideration towards our colleagues' families," he said.

In 2011, Al-Shabaab abducted the two Spanish women, Serra from Girona (Palafrugell) and Thiebaut from Madrid, both working as logisticians for international medical charity, MSF, and took them across the border into Somalia.

The abduction was the third incident of foreigners being abducted in the East African nation which neighbors the lawless Horn of Africa nation in just over a month in October 2011.

The Dadaab refugee complex shelters more than 460,000 refugees. A third of this refugee population arrived in 2011 alone, fleeing the conflict, drought, famine and human rights abuses in Somalia.

The camps in Dadaab opened two decades ago and were originally designed to host some 90,000 refugees.

Since Kenya sent troops across the border into Somalia to dislodge Al-Qaida linked Al-Shabaab in October 2011, northern and parts of eastern Kenya have been hit by a series of attacks, many targeting local security forces and humanitarian workers.