A suicide bomber blew up a vehicle outside a presidential palace in the southern Yemeni city of Hadramout on Saturday, killing at least 20 elite Republican Guards and injuring dozens.

"The bodies of 20 soldiers were taken to the mortuary and there are many others wounded," said a medic at the Ibn Sina hospital in the Hadramawt provincial capital Mukalla.

The victims were believed to have been under the command of outgoing long-term President Ali Abdullah Saleh's son Ahmed.

No group has yet claimed responsibility for the attack.

Yemen's south is a turbulent region where secessionists are seeking to revive a socialist southern state. An active wing of al Qaeda has also taken root in the region.

Earlier on Saturday the country's new president, Abed Rabo Mansour Hadi, was sworn into office.

Yemen's electoral commission on Friday officially announced that the former vice president won the single-candidate presidential election. The vote was part of a US-sponsored power transitional deal drafted by Saudi Arabia and other Gulf nations.

ccp/rc (AP, AFP, Reuters)