Yemen's neighbours urged the UN Saturday to move forcefully over the deteriorating security situation, saying they will themselves act if the rival factions there do not resolve their differences.
The call, at a meeting in Riyadh of the Gulf Cooperation Council, came as Shiite militiamen behind a power grab in Yemen fired live rounds to disperse thousands of protesters.
Home to Al-Qaeda's deadliest branch and a key US ally in the fight against the group, Yemen has descended into chaos since the militia, known as Huthis, seized Sanaa in September.
Matters worsened last month when they ousted the government.
Foreign ministers of the six GCC member countries urged the "UN Security Council to take a decision under Chapter Seven of the United Nations Charter", which allows the use of military force if there are threats to peace.
They also asked for an urgent meeting of the Arab League and of the Organisation of Islamic Cooperation.
In a final communique, they called for immediate international steps to "guarantee the safety of President Abedrabbo Mansour Hadi and Prime Minister Khalid Mahfoudh Bahah as well as other officials" who have been under de facto house arrest since January.
UN Secretary General Ban Ki-moon has warned that Yemen is falling apart and said the Western-backed Hadi should be restored to power.
The GCC also called on world powers to reject a "constitutional declaration" by the Huthis a week ago, under which they dissolved the government and parliament and tightened their grip on power.
They said they hope ongoing UN efforts in Yemen will lead to an agreement by all parties there based on "preserving legitimacy" and "resuming the political process".
Failing that, and without elaborating, they said they would take "measures that will enable them to preserve their vital interests in Yemen's security and stability".
In the city of Ibb, which the militia has held since last year, protesters chanted: "Huthi, Iran: Yemen is not Lebanon!", in a reference to predominantly Shiite Iran's alleged support for the militia.
Witnesses said the Huthis wounded at least six people when they fired warning shots to disperse the protest.
Similar demonstrations took place in the Shiite-populated city of Dhammar which is also under Huthi control, and the southern city of Daleh, where protesters demanded political parties end their UN-brokered talks with the militia in Sanaa.
In the capital, hundreds protested describing the militia as "gangs that could not build a state".
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- Protesters 'tortured' -
Meanwhile, the family of demonstrator Saleh Awadh al-Bashiri, detained by the Huthis on Wednesday at a protest against their takeover, said he had died of torture wounds suffered in captivity.
Another two protesters who were held with him have been hospitalised after being found wounded and left on a street.
The families posted pictures on social media they said were of their sons, showing parts of their bodies bruised and swollen from beatings.
On Sunday, the Huthis announced a ban on all demonstrations against them unless they are authorised by the interior ministry, which itself is now under their control.
The militiamen have been accused of attacking and detaining protesters as well as reporters covering demonstrations against their power grab.
Meanwhile, more countries shut their embassies, with Spain and the United Arab Emirates becoming the latest to announce on Saturday they had suspended operations at their missions in Sanaa.
The UAE foreign ministry said it has also evacuated all staff, following a similar move by Sunni-dominated GCC leader Saudi Arabia.
"This decision comes in light of the increasingly deteriorating political and security situation" and the "unfortunate events with the Huthis undermining legitimate authority in the country", the UAE said in a statement carried by the official WAM news agency.
The United States, France, Germany, Italy, Britain and the Netherlands have also closed their embassies and withdrawn staff for security reasons.
Spain said it was temporarily suspending embassy activity in Yemen "in light of the current situation of insecurity and instability in Sanaa".
Madrid's embassy had advised all Spanish citizens to "temporarily" leave Yemen, the foreign ministry said.
And the Turkish foreign ministry "strongly" advised its citizens to leave also.
The Huthis had said Western powers had no reason to shut their embassies, insisting that security was solid in the capital.
Tehran also criticised the "hasty action" of closing embassies, insisting the Huthis were fighting "corruption and terrorism".
Following consultations in New York on Thursday, Britain said it would work with Jordan on a resolution to outline the Security Council's stance on Yemen.