Sanaa, Yemen - Yemen has moved closer to chaos as talks between the government and Shia Houthi rebels, who have established a growing presence in the capital over the past week, broke down and tens of thousands of people took part in an anti-Houthi march through the city centre.
For the past week, growing numbers of Houthi supporters have been arriving at encampments on Sanaa's outskirts, marching through the city daily while the movement's leader Abdelmalek al-Houthi has made repeated demands that a recent fuel price hike be reversed and the government be dissolved, threatening an expanding campaign of civil dissent.
Houthi officials have repeatedly said that they intend to topple the government through peaceful means - but also say that they reserve the right to respond with force if attacked by the security forces.
On Saturday evening, a delegation sent to the Houthi stronghold of Sadah in north Yemen by President Abd-Rabbu Mansour Hadi returned to the capital empty-handed after three days of talks with al-Houthi.
The negotiations had initially seemed to be fruitful, with Hadi offering to reshuffle the government and form an economic committee to review the decision to cut fuel subsidies, several people with knowledge of the situation said.
But "the first round [of talks] fell through," an official told Al Jazeera.
Hadi appears increasingly convinced that the Houthis plan on laying siege to the capital, and preparing for the worst.
"The army is ready to address any threats," the same official said in response to questions about the likelihood of fighting in the capital.
The president's confidence that the Houthis can be pushed back is likely to have been boosted on Sunday when tens of thousands of people attended a rally organised by Islah, Yemen's main Sunni Islamist party. Although the event, which saw protesters flood the main thoroughfare Zubairi Street before arriving at Bab al-Yemen, the main gate to the historic Old City, was billed as a "unity march", anti-Houthi rhetoric was the order of the day.
They are terrorists, like the Taliban in Afghanistan.
"Jumuhouria, Jumuhouria, la Houthia, la Houthia," came one chant, referring to the widespread belief that al-Houthi wants to be installed as a king-like Imam, heading a strict Islamic state. "Republic, republic, Houthis no, Houthis no," was another slogan.
Other chants were more explicit. "This is the last day of Abdelmalek al-Houthi... Houthis we will break your arm," went one.
"The Houthis want to take our country by cutting our throats," said Mohammed al-Sahami, 38, a tribesman from Mareb province who carried a picture of his cousin Mohammed, a soldier who was killed during fighting between the Houthis in the northern province of al-Jawf earlier in the year. "They are terrorists, like the Taliban in Afghanistan."
The Houthis, for the better part of a decade the underdogs in an on-off civil war with the regime of former President Ali Abdullah Saleh have made significant political and military gains since the 2011 uprising that led to Saleh's ouster, consolidating control over Sadah and seizing Amran province, which separates Sadah from the capital, after several rounds of fighting with Sunni Islamist and tribal militias.
Intense fighting is ongoing in al-Jawf, and many observers are worried that what was initially a fight between rival political powers is taking on increasingly sectarian overtones.
The Houthis have made major gains since 2011, but in trying to force Hadi into a climbdown, al-Houthi has gone too far, said Abdulghani al-Iryani, a Sanaa-based political and economic analyst.
"Clearly, he has overplayed his hand," al-Iryani said. "He thought he could take this as far as possible. But now the government has had enough and Islah is trying to force him to stick to his position. Abdulmalek does not want to commit suicide, though, and I think if President Hadi gives him the chance for a face-saving deal he will take it."
Houthi supporters marched into the city centre on Sunday, calling, as they have for the past week, for the government to be dissolved and the fuel subsidy to be reinstated.
Most of those attending the Houthi marches have entered the city centre unarmed, but government officials claim that those staying at camps in the north and south of the city are well-supplied and ready for war. Houthi officials deny this, however, and claim that a deal is close, with Hadi preparing to agree to a cut in the fuel price and the creation of a new government.