The re-alignment of Saleh’s forces with the Saudis would mark a significant turn in a war that is part of a wider struggle between regional powers Saudi Arabia and Iran.
The bloodshed has compounded the woes of one of the Arab world’s poorest countries and left at least 10,000 dead as hunger and disease have spread.
At the United Nations, U.N. Secretary-General Antonio Guterres urged the warring parties to stop all ground and air assaults. He also called for the resumption of all commercial imports into Yemen, saying millions of children, women and men were at risk of mass hunger, disease and death.
However, in a speech late on Sunday, Saleh formally annulled his alliance with the Houthis and pledged to step up his fight.
Saleh, who dominated Yemen’s heavily armed tribal society for 33 years before quitting in the aftermath of the Arab Spring uprisings in 2011, and the Shi’ite Muslim Houthis had made common cause against Hadi loyalists.
But they vied for supremacy over the territory they ran together, including Sanaa, which the Houthis seized in September 2014, and their feud burst into open combat on Wednesday.
Houthi spokesman Mohammed Abdul Salam claimed significant gains in the battle for Sanaa on Monday.
“With the aid and approval of God, the security forces backed up by wide popular support were able last night to cleanse the areas in which the militias of treason and betrayal were deployed,” he said in a statement.
The Houthi movement’s TV channel al-Masirah and witnesses said Houthir fighters had seized the downtown home of Saleh’s nephew Tareq, an army general.
Residents said the warring sides traded heavy automatic and artillery fire as the Houthis advanced in the central Political District, which is a redoubt of Saleh and his family.
“We lived through days of terror. Houthi tanks have been firing and the shells were falling on our neighborhood,” said Mohammed al-Madhaji, who lives in the frontline district.
“The fighting has been so violent we feel we could die at any moment. We can’t get out of our homes.”
Houthi media and political sources also reported that the Houthis also advanced toward Saleh’s birthplace in a village outside Sanaa where he maintains a fortified palace.
