Houthi fighters, backed by supporters of former Yemeni President Ali Abdullah Saleh, have entered the provincial capital of the Shabwa province in eastern Yemen, despite intense Saudi-led air strikes against the group.
Residents said local tribal chiefs and security officials facilitated the entry of the Houthi forces to the city of Ataq on Thursday, where they took control of the offices of the local government and security forces compounds.
It was the first time that the Houthis and their allies had entered the city, bringing them closer to the country's most prized economic asset, the Belhaf natural gas facility and export terminal, on the Arabian Sea about 160 km to the southeast.
A great nation like Yemen will not submit to bombing. Come, let us
all think about ending war. Let us think about a ceasefire...Let us
prepare to bring Yemenis to the negotiating table.
The air campaign failed to stop the Houthis and soldiers loyal to Saleh entering central Aden, but the coalition says it has cut Houthi supply lines, destroyed weapons depots and pushed them back in some southern provinces around Aden.
Meanwhile, the World Health Organisation (WHO) says at least 643 people have died and more than 2,200 have been injured in the conflict so far.
Tens of thousands of families have also been displaced and the WHO has warned that the situation in the Arabian Peninsula nation is critical.
In a speech on Thursday in Tehran, Iran's President Hassan Rouhani called for an end to the air strikes in Yemen, saying countries in the region should work towards a political solution.
"A great nation like Yemen will not submit to bombing. Come, let us all think about ending war. Let us think about a ceasefire...Let us prepare to bring Yemenis to the negotiating table," he said.
Saudi Arabia and its Gulf allies accuse Iran of arming the Houthi fighters but Iran denies the allegations.
Al-Qaeda continues its advance
Earlier in the day, residents of al-Siddah district in central Yemen said they woke to find al-Qaeda flags flying over local government offices, Reuters news agency reported.
They said a group of al-Qaeda gunmen led by a local commander known as Ma'mour al-Hakem, took over the district at night. Residents said the Houthis, who had been in control of the town for more than two months, retreated without a fight.
The United States defence secretary has said that the escalated conflict has provided al-Qaeda with an "opportunity" to gain new territory in Yemen. This is despite confirmation from the US that it is expediting advanced arms shipments to Saudi Arabia.
Against this backdrop of escalating tensions, the first medical supplies have started arriving in Aden: the medical aid group Doctors Without Borders said they have made it to some of the city's hospitals.
It said a boat carrying 2.5 tonnes of medicine had docked in Aden, the first shipment the group has delivered to the city since the fighting there escalated.
For its part, the International Committee of the Red Cross (ICRC) said that a surgical team also arrived by boat on Wednesday in Aden.
"It's nearly catastrophic," Marie Claire Feghali, ICRC's spokesperson in Yemen, told Reuters news agency.
"Shops are closed, so people cannot get food, they cannot get water. There are still dead bodies in the street. Hospitals are extremely exhausted."
Source Al jazeera