ADEN: At least 80 troops from Yemen's secessionist Southern Transitional Council (STC) have been killed in fighting with Saudi-backed forces and strikes since Friday, a military official from the group told AFP on Sunday.
At least 152 members of the UAE-backed STC forces were wounded and 130 were taken captive, the official said, giving a preliminary toll of casualties since the start of the operation.
Saudi-backed forces began on Friday operations to retake swathes of territory seized by the UAE-backed STC, as a struggle for dominance between forces backed by Riyadh and Abu Dhabi deepened a rift between the two Gulf allies.
Most of the casualties had occurred in strikes by the Saudi-led coalition that targeted military camps held by the separatists, the official said, including Al-Khasha and Barshid military camps in Hadramawt province.
An official with the Saudi-backed forces told AFP later Sunday that at least 14 of their fighters had been killed in fighting and over 30 wounded during the offensive.
Yemen's presidency on Saturday announced the retaking of resource-rich Hadramawt, following an apparent retreat of the STC.
Riyadh-aligned government military officials on Saturday also said authorities in neighbouring Mahra province had switched back their allegiance without any resistance.
On Sunday, Saudi-backed forces were consolidating positions in Mukalla, the capital of Hadramawt province, two government military officials told AFP.
Riyadh and Abu Dhabi have long supported rival groups in Yemen's divided government.
A December offensive by the STC, in which it took control of Hadramawt and Mahra, angered Saudi Arabia, exposing fissures in the ties between the two oil-rich powers.
The Saudi-led coalition launched repeated warnings and air strikes over the past week, including one on an alleged Emirati arms shipment to the separatists.
On Friday, a strike on the Al-Khasha military camp in Hadramawt left 20 dead, according to an earlier toll from the separatist group.
On Saturday, a military official with the STC told AFP Saudi warplanes had carried out "intense" air strikes on another of the group's camps at Barshid, west of Mukalla.
The Yemeni government is a patchwork of groups that includes the separatists, and is held together by shared opposition to the Iran-backed Houthis.
The Houthis pushed the government out of Yemen's capital Sanaa in 2014 and secured control over most of the north.
The Iran-backed group has been at war with the government, backed by a Saudi-led coalition since 2015, in a conflict that has killed hundreds of thousands of Yemenis and triggered a major humanitarian crisis.