ADEN, Yemen, Aug 30 (Xinhua) -- An explosion caused by a roadside bomb struck a motorcade of senior security commanders in the southern port city of Aden on Friday, leaving five bodyguards injured, a military official told Xinhua.

"The roadside bombing aimed at assassinating the leader of the Security Belt forces Wadah Omar along with other officers in Sheikh Othman neighborhood of Aden," said the military official on condition of anonymity.

"All the security commanders survived but around five of their bodyguards were seriously injured," said the official.

The security commanders loyal to the Southern Transitional Council (STC) were "overseeing a campaign to track a number of terrorist elements in Sheikh Othman neighborhood."

Elsewhere in Aden's northern main entrance, an attacker used a booby-trapped motorcycle and targeted a checkpoint of the Security Belt forces in Dar Saad neighborhood.

"The attack left an unknown number of casualties among the security soldiers who were standing at the checkpoint," a police officer said anonymously.

The motorcycle explosion burned a number of military vehicles parked around the checkpoint in Aden's northern entrance, according to the officer.

Warplanes hovered over Aden's airspace following the twin explosions.

Heavy security forces belonging to the Aden-based STC were deployed across Aden's streets and began tracking suspected terrorists.

Considered as Yemen's temporary capital, Aden is where the Saudi-backed Yemeni government has based itself since 2015.

The impoverished Arab country has been locked in a civil war since late 2014, when the Houthis overran much of the country and seized all northern provinces including the capital Sanaa.