Thousands of Shia Houthi rebels have further strengthened their positions in the Yemeni capital, as their supporters gathered on the outskirts of Sanaa to demand an end to fuel price rises and for the government to step down.
Chanting slogans against the government, men waved guns as they struck their fists in the air, as trucks loaded with Houthi supporters converged on the city on Wednesday.
Protesters were responding to a call by Abdel-Malek al-Houthi, the main leader of the heavily armed Hawthi group that overran northern cities. He has given the government until Friday to meet their demands of reinstating fuel subsidies.
We didn't come here for fun or for the sake of an outing, we came here to take down the government, to end the rations [fuel] and to implement the decisions of the national dialogue. This is what we demand and what our leader Abdul Malek al-Houthi demands
Men armed with Kalashnikovs manned checkpoints around the protest camps, while Yemeni military aircraft circled in the skies of the capital.
The Houthis, who seek more power for their sect in north Yemen, battled the central government in the last decade, but committed to peaceful transition after President Ali Abdullah Saleh was ousted in 2011.
On Monday, the Houthis had mobilised tens of thousands of supporters to protest against the cuts in fuel subsidies after Houthi warned the government in a speech "against any aggression against our revolutionary Yemeni sons".
In Wednesday's protest, the demonstrators said they will not give up on their demands.
"The person who brought us here is our leader, Abdul Malek, and we are awaiting his instructions to go to Sanaa - we will go there to get rid of the oppressors, to end corruption and the corrupt government," supporter Noor Eldeen Ahmed Ali, told the Reuters news agency.
"We didn't come here for fun or for the sake of an outing, we came here to take down the government, to end the rations [fuel] and to implement the decisions of the national dialogue," supporter Adel Ahmed al-Shami said.
"This is what we demand and what our leader Abdul Malek al-Houthi demands."
The Yemeni government increased fuel prices after spending about $3bn on energy subsidies last year, nearly a third of state revenue.
Negotiating lasting truce
Military officials said that Yemen's elite "Presidential Forces" were on standby in case of any attack, taking positions near government buildings, foreign missions and main intersections.
They spoke on condition of anonymity because they were not authorised to speak to journalists.
Yemen's Supreme Security Committee, the country's most senior security body, warned on Tuesday it will take "all measures to ensure the safety and security of the country".
The committee listed what it said were "worrying signs" of fighters deploying on rooftops in some areas of the capital, as well as the armed Houthi convoys entering the capital and setting up checkpoints.
President Abd-Rabbu MansourHadi on Wednesday mandated a committee with the task of negotiating a lasting truce with the Houthis, according to a government official.
The official said the committee would meet with Houti leaders in Saada, in northern Yemen, on Thursday in an attempt to convince fighters to leave the capital.
Houthi fighters have resorted to military force this year to consolidate their hold on the north, advancing towards the Sanaa and fighting rival Sunni factions, in actions threatening the delicate transition of power in the turmoil-prone country.
The Houthis defend their territorial advance as simply an outgrowth of their growing popular support in those areas. Critics see an attempt to strengthen their position at a critical moment in the transition process.
The majority Sunni country is edging towards a federal system that would devolve more power to the regions.
The national unity government formed after Saleh's overthrow excludes Houthis, although Hadi has promised a more inclusive government after a new constitution is passed later this year.