Gunbattles erupted in the Yemeni capital Sana'a Sunday as an alliance between the Iran-backed Shi'ite rebels known as the Houthis and former president Ali Abdullah Saleh appeared to have fallen apart.
The two sides joined ranks three years ago and swept across the capital, Sana'a, forcing the country's internationally recognized President Abed Rabbo Mansour Hadi to flee the country and seek military intervention led by Saudi Arabia.
The Houthis' political office have accused Saleh of staging a "coup" against "an alliance he never believed in" after he offered to initiate talks with the Saudi coalition. In a televised speech, Saleh asked for an end to the siege on Yemeni ports and offered, in exchange, to "turn a new page" and "deal with them in a positive way."
Clashes between fighters loyal to Saleh and the Houthis first erupted last week when Saleh accused the rebels of storming his giant mosque in Sana'a and attacking his nephew, the powerful commander of the special forces, Tarek Saleh.
Both sides have set up checkpoints, placed snipers on rooftops and sealed off entrances to the city. But many state institutions, including the airport, state TV headquarters and the official news agency, remain under the control of the Houthis.
United Nations Secretary-General Antonio Guterres on Sunday urged warring parties in Yemen to stop all ground and air assaults. In a statement released Sunday, the U.N. said the sharp escalation of armed clashes and airstrikes in Sana'a has already resulted in dozens of deaths and hundreds of injuries, including civilians.
Fighting is restricting the movement of people and life-saving services within Sana'a city. Ambulances and medical teams cannot access the injured and people cannot go outside to buy food and other necessities, it said. Aid workers are unable to travel and implement critical life-saving programs at a time when millions of Yemenis rely on assistance to survive.
Yemen is one of the Arab world's poorest countries. Since 2015, it has been locked in a devastating civil war pitting Saudi-backed government forces against Iranian-supported rebels.
Yemen has become a humanitarian catastrophe, with more than 10,000 people killed in the fighting and at least 2 million displaced. A cholera outbreak has infected nearly 1 million people.