STC military spokesman Mohammed al-Naqib told Reuters the attack took place while a foot patrol of troops was following up on terrorist elements in Wadi al-Naba, outside Wadi Omran in Mudiya district in eastern Abyan, where extremist elements are active.

It is clear that the terrorist elements are being prepared by parties, led by the Houthi movement, to try to resume their manoeuvres, at least with improvised explosive devices (IEDs), planted in more than one area in Abyan, al-Naqib said.

Earlier, four soldiers from the Southern Transitional Council's Shabwa Defence Forces were killed when an improvised explosive device targeted an ambulance for the forces in the al-Musaina'a area of Upper Egypt district, west of the southern Shabwa oil province, where "terrorist elements" are active.

This follows attacks carried out by the group since the beginning of the year in the same province in response to the military operation launched by forces loyal to the STC almost a year ago that killed dozens of soldiers.