UN investigating reported kidnappings of a UN staff member and driver in Yemen

A U.N. official says the United Nations is responding to reports that a U.N. staff member and driver have been kidnapped in Yemen's capital, Saana.

The official, speaking on condition of anonymity because of the sensitivity of the issue, had no further details on Tuesday's reported abduction which the U.N. is investigating.

Abductions are frequent in Yemen, an impoverished nation where armed tribesmen and al-Qaeda-linked militants take hostages in an effort to swap them for prisoners or cash.

Yemen is engaged in a rocky political transition since longtime autocrat Ali Abdullah Saleh stepped down in 2012 following mass popular protests. Multiple armed groups across the country resist state authority.