SANAA: A 48-hour truce aimed at ending Yemen's civil war came under pressure on Saturday as residents said fighting was still going on in parts of the country.

The ceasefire declared by the Saudi-led military coalition trying to restore a Saudi-backed government raised hopes of an end to a 20-month conflict that has drawn in regional rivals Iran and Saudi Arabia and left Yemen on the verge of famine.

It appeared largely to be holding on Saturday but was strained by gun battles in the key western city of Taiz, and by air strikes by the Saudi-led coalition reported by residents in villages east of the capital Sanaa.

The Soviet-era Tochka missile was fired into the eastern desert province of Marib, Brigadier General Ahmed al-Assiri told Saudi-owned al-Hadath TV.

"Perhaps on the second day of the truce we will witness a sense of responsibility, otherwise the situation will be dealt with proportionately," Assiri said.

Brigadier General Sharaf Luqman, a spokesman for the Yemeni armed forces allied with the Houthis, said the movement remained committed to a cessation of hostilities but was ready to "defend Yemen's independence in the event of continuing aggression".

SIEGE OF TAIZ

Yemen's Saudi-backed government, led by President Abd Rabbu Mansour al-Hadi, and the Iranian-aligned Houthis blamed each other for the fighting in mountainous Taiz, where thousands of civilians are trapped and many have been wounded. Government forces this week made advances on Taiz, threatening to break a year-long Houthi siege.

Saudi Arabia and allied Sunni Muslim Gulf states began a military campaign in March last year to prevent the Houthis and forces loyal to ex-president Ali Abdullah Saleh taking control of the whole country.

The Saudi-led coalition expelled enemy fighters from the southern port city of Aden last summer but the Houthis continue to hold swathes of territory including the capital, with help from Saleh loyalists.

More than 10,000 Yemenis have been killed in the war.

A coalition statement carried by the Saudi Press Agency said the truce had started at noon (4.00 am ET) and could be extended if the Houthis showed commitment to it and allowed aid into areas such as Taiz.

The Houthis had said on Wednesday they were ready to stop fighting and join a national unity government.

Saturday's ceasefire was announced after diplomacy by US Secretary of State John Kerry, but Hadi's camp said that, although its Gulf allies had been consulted, his government had been sidelined.

The coalition has not said whether it accepts a U.N.-brokered peace plan, which would give the rebels a share of power.

MISSILE

Hours before the ceasefire began, a soldier in Saudi Arabia was killed by a missile fired by the Houthis, the Interior Ministry said, the type of cross-border attack that the Saudis insist must stop.

The coalition said in its statement that any "military movements" by Houthi forces would be "addressed by the coalition", and that controls imposed on Yemen's ports and airports to stop arms getting to the enemy will remain in place.

The near-blockade on air, sea and land access has caused food shortages in a country that imports over 90 percent of its staple foods, driving up prices and making it impossible for many Yemenis to feed themselves and their families.

No side has emerged as the dominant force in a war that has dragged into stalemate, displaced more than 3 million people and given room for a powerful branch of al Qaeda to expand its operations.

The frontline has changed little over recent months, with the Houthis and their allies holding most of Yemen's northern half, including the capital Sanaa, while forces loyal to Hadi share control of the rest of the country with local tribes.

Hadi's government says the Houthis illegally seized power in a coup backed by Iran, and demands that they quit the cities they seized and hand over heavy weapons before any political settlement starts.

The Houthis say they took power to end corruption and to get rid of the Sunni Islamist militants who they say expanded their influence during Hadi's presidency.