Mary Jean Lacaba, Eugenio Vagni and Andreas Notter were seized exactly a week ago by a group of unidentified armed men on the southern Philippine island of Sulu after a visit to the Jolo provincial jail, where they were working on a water and sanitation project to improve living conditions for the detainees.

"I appeal to those who are holding Mary Jean, Andreas and Eugenio to let them go as quickly as possible," said Alain Aeschlimann, the ICRC's head of operations for East Asia, Southeast Asia and the Pacific in Geneva. "We want to have them back safe and sound. Their children, spouses, parents, siblings and loved ones are anxious and waiting for them to come home."

The ICRC has been in contact with the three staff members several times since they were kidnapped on 15 January. The last time the three were able to call was on 19 January.

"We hope that we'll hear their voices again soon and that they remain unharmed," said Aeschlimann. "We also continue to hope that this difficult situation will have a positive outcome."