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The  in the desert region have seen power to and fro between the two camps for several weeks after the Sanaa-based rebels launched the offensive into the neighbouring Marib governate.

The Houthi military offensive is thought to be the largest since 2015 when the rebels penetrated into the southern coastal city of Aden, prompting a  to intervene.

Several prominent Houthi leaders and high-ranking commanders have been killed in the raging clashes across Marib and Jawf. Footage and images shared online showed a funeral convoy for the Houthi fighters killed in the offensive.

Similarly, a number of senior tribesmen, including the representative of Yemen's Islah party in the parliament, Sheikh Rabish Al-Alayai, have been killed in the ongoing fighting.

"Marib hosts almost 3 million civilians, of which almost 2 million are internally displaced persons [IDPs] that have moved to the governate because it has become safe and secure over the past few years," Nadwa Dawsari, Yemen expert and non-Resident Scholar at Middle East Institute told °®Âþµº, warning "this Houthi offensive puts the lives of 3 million Yemenis at risk - it is a major humanitarian disaster."

The Houthi military offensive is thought to be the largest since 2015 when the rebels penetrated into the southern coastal city of Aden

"If the Houthis do manage to capture Marib, it would solidify their total control of the north and they will not stop there. The next step would be for the rebels to push south towards Shabwah and Hadramawt and even further north to the Saudi border. 

"A Houthi capture of Marib will tip the military scales in favour of the rebels - if this happens, we can kiss the peace process, negotiations and any potential for sustainable peace in Yemen's future, goodbye," Dawsari added.

On Wednesday,  power-sharing deal became the first casualty of ongoing fighting across the country.

Yemen's southern separatists announced their withdrawal from talks over the , in the latest setback for the troubled process.

The Southern Transitional Council (STC) said in a statement that it had sent a letter to the Saudi authorities confirming "the suspension of its participation in the ongoing consultations to implement the agreement".

The Riyadh Agreement which was struck late last year was designed to mend a rift between allies in the war against Houthi rebels who have seized much of Yemen's north.

It sought to quell the "civil war within a civil war" and was hailed as a possible stepping stone towards ending the wider conflict.

The separatists said Wednesday that their decision to pull out of the talks was due to ongoing military escalation in the flashpoint province of Abyan, and the rupture of an agreed ceasefire.

The STC's Vice President Hani Ben Brik said in a tweet that the separatists were committed to the original agreement but that their move was aimed at pushing for a full commitment to the deal.

The breakdown between the STC and the government has complicated the long and separate conflict between the Saudi-led military coalition and the Houthi rebels who control the capital Sanaa.

The STC proclaimed self-governance in the south in April, only to abandon that stance last month and pledge to implement the stalled peace deal.

They said they came back to the Riyadh Agreement in late July under pressure from United Arab Emirates and Saudi Arabia, which had proposed a plan to "accelerate" the power-sharing process.

The plan called for the Yemeni prime minister to form a new government within 30 days, as well as the appointment of a new governor and security director for the second city Aden, where the government is now based.

If the Houthis do manage to capture Marib, it would solidify their total control of the north and they will not stop there

The tussle for control of the south exposed divisions between the coalition partners - Saudi Arabia, which backs the government, and the United Arab Emirates, a backer and funder of the STC. 

The divisions have taken attention away from other governances across the country where tribal forces have been left to fend for themselves as Houthi rebels continue to march into new frontlines.

More than 100,000 people, mostly civilians, have been killed and millions displaced in  which has triggered what the United Nations has called the world's worst humanitarian disaster.

Agencies contributed to this report.

Yemen In Focus is a regular feature from °®Âþµº.

Sana Uqba is a journalist at °®Âþµº. 

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