The Arab coalition on Monday (April 27th) rejected a declaration of self-rule by separatists in Yemen's south and demanded "an end to any escalatory actions".
The breakaway declaration made Sunday significantly complicates Yemen's wider conflict, between Yemen's government, backed by the Arab coalition, and the Iran-backed Houthis (Ansarallah), who control much of the north.
Separatists in the south, which used to be an independent country, have repeatedly agitated to break away again -- a campaign that was temporarily put to rest with a power-sharing deal signed in Riyadh last November.
But on Sunday the Southern Transitional Council (STC) declared self-rule in southern Yemen, accusing the government of failing to perform its duties and of "conspiring" against the southern cause.
Aden residents reported heavy deployments of STC forces, and a separatist source said they had set up checkpoints "at all government facilities, including the central bank and port of Aden".
The Yemeni government condemned the move and warned it could lead to a "catastrophic and dangerous" outcome.
The Arab coalition reiterated the need "to promptly implement the Riyadh Agreement", according to the Saudi Press Agency.
"The coalition demands an end to any escalatory actions and calls for return to the agreement by the participating parties," the coalition said.
Key coalition partner the UAE, which has supported the STC, also stressed the importance of abiding by the Riyadh pact.
"Frustration over delay in implementing the agreement is not a reason to unilaterally change the situation," UAE's minister of state for foreign affairs Anwar Gargash said in a social media post.
"We have full confidence in Saudi Arabia's keenness to implement the agreement."
Saudi state minister of foreign affairs Adel al-Jubeir said the kingdom and the UAE "strongly believe that the internationally-backed Riyadh agreement has guaranteed an opportunity for the brotherly Yemeni people to live in peace".
"We reject any hostilities that will jeopardise the safety and stability of Yemen."
Aftermath of flash floods
Yemen's government declared Aden a "disaster area" on April 21st, following flash floods in which 14 people died, including five children, and at least 45 people were injured. The floods also destroyed homes, cars and property.
The government allocated one billion riyals ($4 million) in emergency relief to assist Aden in the opening of roads, removal of debris and compensation of affected residents, Deputy Prime Minister Salem al-Khanbashi said last week.
The Supreme National Emergency Committee dispatched field teams to remove debris and pump water to prevent the spread of water-borne diseases and malaria-carrying mosquitoes, said al-Khanbashi, the committee's chairman.
"The ministry is concerned about the spread of epidemics such as the dengue fever and other fevers due to standing rainwater," Deputy Minister of Health Abdul Raqeeb al-Haidari told Al-Mashareq at the time.
"The magnitude of the disaster that befell Aden far exceeds available resources," emergency committee co-ordinator Jamal Belfaqih told Al-Mashareq.
"The situation in Aden requires that all official agencies join forces with civil society organisations and receive help from international organisations and the Arab coalition to mitigate the damage to the population," Belfaqih said.
The emergency committee had last week arranged to provide urgent financial support and shelter to families whose houses were damaged.
The King Salman Humanitarian Aid and Relief Centre (KSRelief) also pledged to provide food baskets to 10,000 families, and the Saudi Development and Reconstruction Programme for Yemen has been removing debris from some streets.
Border closures extended
Meanwhile, the Yemeni government last week extended the closure of land, sea and air border crossings until further notice as part of precautionary measures taken to fight the novel coronavirus (COVID-19) pandemic.
Yemen reported its first coronavirus case on April 10th in Hadramaut province.
In an April 20th meeting to address the situation, the Supreme National Emergency Committee agreed to strengthen preventive measures at border crossings and facilitate the entry of commercial and relief shipments.
"Yemen cannot close its land, sea and air crossings completely as the country is a net food importer," economist Abdul Aziz Thabet told Al-Mashareq.
Prime Minister Moeen Abdulmalik said the Yemeni government will not hesitate to take all necessary measures to protect Yemeni citizens from coronavirus.
"Some private sector companies have announced they will help outfit hospitals with equipment," Deputy Minister of Health Abdul Raqeeb al-Haidari told Al-Mashareq.
These efforts will support the Ministry of Health, which has been working with the World Health Organisation (WHO), KSRelief and the World Bank, he said.
In Hadramaut province, a total lockdown was imposed on al-Shahr and al-Ghayl districts, with a partial lockdown on the rest of the province.
Al-Haidari said neighbouring Shabwa, al-Mahrah and Wadi Hadramaut have closed their crossings with the Hadramaut Coast, as "a precautionary measure to encircle the epidemic in the narrowest geographical area".