Schools and shops in Yemen's capital were closed on Sunday as clashes erupted in Sanaa following the collapse of a rebel alliance.
Residents of Sanaa neighbourhoods said they had barricaded themselves in their homes to avoid snipers and shelling as clashes flared up around key ministries where the two sides had been working together just days before.
A number of streets in central Sanaa were cut off by forces loyal to powerful ex-president Ali Abdullah Saleh, who were deployed heavily in anticipation of a possible attack by the Houthi rebels.
Loyalists of the former strongman renewed a bid to seize control of al-Jarraf district, a stronghold of the Houthis, while the rebels fortified their positions with dozens of vehicles mounted with machine guns.
The education ministry cancelled classes on Sunday, normally the start of the school week, out of concern for students and teachers.
Witnesses said some of the bodies from previous days' clashes were still strewn in the capital.
Iyad al-Othmani, 33, said he had not left his house for three days because of the clashes and tensions.
Mohammed Abdullah, a private sector employee, said his street had been cut off by militiamen and he was staying home to avoid checkpoints.
"Sanaa is becoming like a ghost town. There is a street war and people are holed up in their houses," according to a local activist who works with the International Organisation for Migration in Sanaa.
"If the confrontation continues, many families will be cut off" and stranded in their homes, he warned.
Yemen's rebel alliance, who has been in control of Sanaa since 2014, has unravelled in recent days with security forces reporting some 60 combatants killed in clashes between the two sides across the capital, including at the international airport.
On Saturday, Saleh reached out to a Saudi-led coalition that launched a military intervention against the Houthis in 2015, offering to "turn the page" if the coalition lifts a crippling blockade on the country.
Sanaa airport and rebel-held sea ports have been under a tightened blockade since a missile fired by the Houthis was intercepted near Riyadh last month.
Saleh's sudden about-face sparked warnings of retribution by the Houthis, who accused him of staging a "coup against our alliance".
Meanwhile, the coalition carried out dawn air raids against Houthi positions in the hills south of Sanaa on Sunday, but it was not clear if the strikes were meant to benefit Saleh's forces.
Saleh's announcement was welcomed by the coalition, which has struggled to achieve any progress against the Houthi-Saleh alliance that had controlled most of northern Yemen since 2015 and forced President Abd Rabbo Mansour Hadi to flee into exile.
The Saudi-owned Al-Arabiya television said coalition aircraft pounded Houthi outposts in southern Sanaa, but gave no details on casualties. Residents reported at least five air strikes shook the highlands of the area.
The Yemen war has claimed more than 10,000 lives since Saudi Arabia and its allies joined the internationally recognised government's fight against the rebels in 2015. The country is now facing what the United Nations has described as the world's worst humanitarian crisis.