Afghanistan's former King Zahir Shah has bestowed the nation's second highest honor on the three U.N. workers held hostage for nearly a month.

He awarded the Sayed Jamaluddin Afghan medals to Annetta Flanigan from Northern Ireland and Shqipe Hebibi of Kosovo at a ceremony in the presidential palace earlier Thursday. The medal is named after a 19th century Islamic scholar.

A U.N. official accepted another medal for the third hostage, Filipino diplomat Angelito Nayan, who is on his way home.

The hostages were freed on Tuesday after 27 days in captivity, but the circumstances surrounding their October 28 abduction in Kabul remain unclear. The U.N. employees were working in Afghanistan to help organize its first-ever free elections.

The Afghan government says the kidnappers were probably bandits, and has promised a full investigation.