The government of war-torn Yemen is struggling to repel rebel attacks on its last major stronghold while also scrambling to combat a devastating famine.
Houthi attacks in the northern Yemeni city of Marib could create a major roadblock for future attempts to negotiate peace in the country, according to the United Nations.
At the same time, some 50,000 people are starving to death in a steadily escalating famine.
The United Nations says Yemen is home to the "world's worst humanitarian crisis". Here is who is involved and what is at stake.
Who are the Houthis?
The Houthi movement was established in the 1990s to represent a branch of Shia Muslims known as the Zaidis.
During the Arab Spring in 2011, the Houthis actively took part in peaceful protests during which they slowly amassed support from both Shia and Sunni Muslims for their calls for regional autonomy in Yemen and condemnation of the then President Saleh’s close ties with the US.
President Saleh was later in 2011 forced to resign - leaving an unstable transitional government to deal with the social, political and economic strife as well as further social uprisings that resulted from the Arab Spring.
During this time, the Houthis had amassed major influence in the northern Saada province of Yemen and eventually established themselves as a strong military group.
By 2014, the Houthis saw the transitional government’s ongoing struggle to restore internal order as an opportunity to extend their influence and take over the capital Sanaa.
While the annexation of Sanaa was peaceful, it was followed by several military strikes and bombings as the rebel group looked to expand its influence.
The attacks drew attention from surrounding countries, namely Saudi Arabia who feared the Iran-backed Houthis could give Iran more power and dominance in the region.
In March 2015, Saudi Arabia, backed by the UAE, the US and other international allies, launched a military offensive and aerial strikes against the Houthis.
Saudi Arabia’s involvement in Yemen intensified attacks from both sides - helping to create one of the worst humanitarian disasters in modern history.
Currently, more than 20 million people in Yemen are suffering from hunger and malnutrition, more than 4 million have fled their homes since the start of the conflict, and 3.3 million people remain displaced.
With the famine only predicted to get worse, both sides have now shifted their offences to the northern desert city of Marib – the last line of defence standing between the Houthis and the country’s richest oil fields.
Here's why that's important
Over the last year, the Houthis have increased their bombings and strikes on Marib, with authorities reporting hundreds of fighters from both sides were killed just last week.
University of Sydney International Relations expert Sarah Phillips said Marib is the coalition’s last stronghold in Yemen.
“The fight for Marib is extremely important for the future of the country, it’s the last place where the internationally recognised government has any meaningful presence,” she said.
UN authorities say the fight in Marib could prove to be a threat to their current attempts to settle the conflict in Yemen and end the war.
“Capturing that (Marib) for the Houthis will help them tilt the talks in their favour because of its geographical significance in terms of where it is due to oil fields and also because by grabbing as much land and resources as they can they increase their power,” Professor Phillips said.
University of Western Australia expert Amin Saikal said US President Joe Biden’s recent decision to halt US support of the Saudi-supported Yemen government could be what’s driving the Houthi offences.
“In the past, Mr Trump has strongly supported Saudi Arabia and the Saudi-led government in Yemen and now President Biden has said he’s not going to do that, this is what perhaps encouraged the Houthis to keep going with the conflict,” Professor Saikal said.
Where does Australia stand?
Since the war began, Australia’s stance on the conflict in Yemen has primarily mimicked the US response. But, the Australian government is yet to act on Mr Biden’s latest move.
“Generally, the Australian government follows the US line on Yemen, we tend to follow the strategies of our key allies,” Professor Phillips said.
As the capital of one of the few oil producing areas left in the country, the possibility of the Houthis gaining control of Marib is causing great concern.
“It’s strategically really significant, because it’s a part of the country where Yemen still has significant oil reserves, if the government is to have any chance of a comeback to reinstate control, Marib is really crucial,” Professor Phillips said.
The UN has reported more than 100 Saudi-led Coalition air strikes against the Houthis since 10 February.
“Saudi Arabia are determined to make sure they (the Houthis) don’t take the country because of their relations with Iran,”
“The more territories the Houthis gain, the more the conflict will be prolonged,” Professor Saikal said.
The humanitarian toll
Before the Houthis escalated their attacks, Marib was a city of refuge for approximately two million displaced people. Now, according to the UN’s International Organisation for Migration, Houthi offences in Marib have already seen more than 106,000 people forced to flee.
Just three weeks ago, the director for the Internally Displaced Persons Camp Management Unit told Reuters that four camps in Marib were hit by Houthi rebels, two of which had to be completely evacuated.
“Should hostilities move towards the city and surrounding areas, it could displace another 385,000 people,” the report said.
The displacements follow a report released by the UN’s World Food Program in February predicting that almost 2.3 million children under the age of five could suffer from acute malnutrition this year and 400,000 could die if they don’t receive the required treatments.
“Without security and stability across the country, and improved access to farmers so that they are provided with the means to resume growing enough and nutritious food, Yemen’s children and their families will continue to slip deeper into hunger and malnutrition,” said QU Dongyu, Director-General of the Food Agriculture Organisation.
The UN High Commissioner for Human Rights said they are calling for an immediate ceasefire and return to peace talks.
“Given the potentially disastrous humanitarian consequences, we call on all parties to the conflict to de-escalate the situation and remind them of their obligations under international law to protect civilians from the adverse effects of the armed conflict,” spokesperson Liz Throssell said.