Houthi fighters have taken full control of Yemen's presidential palace in the capital Sanaa after a brief clash with the compound's security guards, witnesses and security sources say.
The development came a day after the parties in the ongoing conflict in the Arabian Peninsula country said at two separate times they had agreed to a ceasefire.
The ceasefires were intended to pave the way for negotiations on Tuesday between the opposing parties: the internationally backed President Abd-Rabbu Mansour Hadi and Ansarallah, the military wing of the Houthi movement.
| Yemen clashes throw capital in chaos
Guards at the presidential palace housing the main office of Hadi said they handed over the compound to Houthi fighters after a brief clash on Tuesday.
Abdul Malik al-Houthi, for years the chief negotiator for Ansarallah, later delivered a speech, reeling off a long list of grievances against the Hadi government.
He is the scion of the Zaidi Shia Houthi family from northwestern Yemen that the movement was named after.
He held Hadi responsible for the instability in Yemen and for failing to implement a peace deal reached in September, the Peace and National Partnership Agreement (PNPA).
"Had the president acted responsibly, ... we the Yemeni people ... would have witnessed a positive reality," Houthi said.
The Yemeni government has previously blamed the Houthis for first reneging on the peace deal.
Khaled al-Hammadi, Al Jazeera's producer in Sanaa, said Houthi fighters had "taken over and controlled completely the presidential palace".
The commander of the presidential guard forces surrendered "the Third Brigade of presidential guards to Houthi fighters without resistance and left the presidential palace", he said.
This brigade, he said, boasts at least 280 Russian late-model tanks.
Separately, Al Jazeera's Omar Al Saleh, reporting from the southern city of Aden, said he had received reports that presidential guards outside Hadi's residence elsewhere in Sanaa had also come under attack from snipers.
He reported, quoting sources, that Hadi was safe but his residence was surrounded by Houthi fighters. It also appeared that Hadi was no longer in control and had run out of options, he said.
The UN Security Council also held closed-door consultations on Tuesday on the worsening crisis in Yemen.
Jamal Benomar, the UN special envoy to Yemen, enroute to Yemen reported to the Security Council on the latest developments.
Al Jazeera's James Bays, reporting from the UN headquarters in New York, said that the UN security council had tried almost all options at its disposal in Yemen, apart from military intervention, which member states were overwhelmingly against.
Mark Lyall Grant, the British ambassador to the UN told Al Jazeera that the goal of the meeting was to release a statement affirming support for Hadi, and "making it clear that the international community will not tolerate the spoilers of the transitional government".
RELATED: Yemen crisis explained
The council later released a statement condemning the violence and expressing concern over the "worsening political and security crisis".
It recognised President Hadi as the "legitimate authority" and called for a return to a full implementation of the PNPA agreement. The council also called for "all parties to rapidly engage in finalising the constitution in a constructive manner".
Ban Ki-moon, the UN secretary-general, called for an immediate halt to the fighting.
He implored all sides to "exercise maximum restraint and take the necessary steps to restore full authority to the legitimate government institutions", a UN spokesperson said.
Ferea al-Muslimi, a Sanaa-based political analyst, told Al Jazeera Hadi had been slow to implement reforms since coming to power, and now he was completely "paralysed".
Al Jazeera's Hashem Ahelbarra, who has reported extensively from the country, said that the Houthis appeared to be giving Hadi a final opportunity to come to a political settlement.
Yemen has been wracked by unrest for months. The Houthi fighters seized large parts of Sanaa in September and repeatedly clashed with troops loyal to Hadi, culminating in Tuesday's takeover of the presidential palace.
Siege of palace
Earlier on Tuesday, Nadia Sakkaf, Yemen's information minister, described on Twitter the assault on the presidential palace despite negotiations between the government and the Houthis.
Witnesses in Sanaa cited by Reuters news agency said there was a brief clash between a Houthi unit and palace guards.
Sakkaf tweeted earlier that the president was under attack since 3pm local time:
Witnesses also said they saw the Houthis seize armoured vehicles that had been guarding the entrances to the palace.
Al Jazeera's Al Saleh said Ali Abdullah Saleh, the long-serving president toppled after mass protests in 2012, still commands a lot of influence in Yemen.
Ex-president Saleh wields clout in the military and among different tribes, he has cobbled together an alliance with the well-organised and well-armed Houthis - said to be backed by Iran - to strike at their common enemies, he said.
It has since been confirmed that only the presidential guard loyal to Hadi had fought against the Houthis in this latest round of fighting while the military and other forces stayed put.
Tuesday's developments came a day after some of the fiercest fighting in Sanaa in recent years, with the Houthis engaging in artillery battles with the army near the presidential palace and surrounding the prime minister's residence.
Nine people were killed and another 90 wounded before a shaky ceasefire came into force on Monday evening.
Source: Al Jazeera and agencies