The United Nations has announced a new ceasefire in war-ravaged Yemen from early Thursday, after a week of escalated fighting sparked new international calls to end the conflict.

While President Abedrabbo Mansour Hadi's government and its Saudi backers said they would support the truce, there has been no word from the Iran-backed rebels who control the capital Sanaa and other areas of the Arabian Peninsula country.

A cessation of hostilities that first went into effect in April ‘will re-enter into force at 23:59 Yemen time (2059 GMT) on 19 October 2016, for an initial period of 72 hours, subject to renewal’, UN special envoy for Yemen Ismail Ould Cheikh Ahmed said in a statement late Monday.

Yemen has been rocked by war since the Shia Houthi rebels and allied forces loyal to ousted president Ali Abdullah Saleh overran Sanaa in September 2014.

The conflict escalated after a Saudi-led Arab coalition began a campaign against the rebels in March 2015.

The UN says the fighting has since killed almost 6,900 people, wounded more than 35,000 and displaced at least three million, with civilians paying the heaviest price amid a worsening humanitarian crisis.

UNICEF's representative in Sanaa, Mohammed al-Assadi, told reporters Sunday that ‘10 million’ children in Yemen need ‘water, food, medicine, social protection, and general services’.

The United States, Britain and the UN peace envoy on Sunday urged the warring parties in Yemen's civil war to declare a ceasefire.

Yemeni Foreign Minister Abdulmalek al-Mekhlafi welcomed the truce which he said will be extended if the rebels adhere to it, activate a truce observing committee, end a months-long siege of Taez and allow ‘unrestricted’ humanitarian aid into the loyalist-controlled third city.

Before the UN announcement, Saudi Foreign Minister Adel Jubeir also said Riyadh was in favour of a truce if the rebels respect it, the daily Asharq al-Awsat reported.

- Sixth truce attempt -

This is the sixth attempt to establish a Yemen ceasefire.

The April truce declared in conjunction with the start of peace talks in Kuwait was hardly observed on the ground, with each side blaming the other for violations.

It collapsed as the talks ended in August with no breakthrough, prompting an intensified round of fighting.

The Arab coalition stepped up its air raids and cross-border attacks from Yemen on Saudi Arabia intensified.

One of the deadliest coalition attacks was an October 8 air raid on a funeral ceremony in Sanaa that killed 140 people and wounded 525, drawing severe criticism of the coalition, which is backed logistically by Washington.

In a rapid escalation, Washington accused the rebels of targeting American warships in the Red Sea on October 9 and 12 with missiles that fell short.

The US then hit radar sites in rebel-controlled territory in Washington's first direct action against the insurgents.

However, de-escalation swiftly followed as the coalition on Saturday acknowledged that one of its warplanes had ‘wrongly targeted’ the funeral in Sanaa based on ‘incorrect information’.

It announced disciplinary measures, compensation for the families of victims and an easing of the air blockade it enforces to allow the most seriously wounded to be evacuated for treatment abroad.

On Sunday, US Secretary of State John Kerry met in London with his counterparts from Britain, Saudi Arabia and the United Arab Emirates along with the UN envoy to discuss Yemen.

‘This is the time to implement a ceasefire unconditionally and then move to the negotiating table,’ Kerry told reporters afterwards.

Earlier this month, the UN envoy had said that a 72-hour ceasefire was expected soon, adding that he hoped to draft a new Yemen peace plan.

The coalition has carried out hundreds of air strikes and provided ground troops to support Hadi's forces but has failed to dislodge the rebels from key areas.

They still control Sanaa, large parts of the north, their historic stronghold, and parts of western and central Yemen.

Government forces have recaptured the south and east but failed to make other significant advances.