Sana'a, Yemen  - The Yemeni government said on Friday it would suspend military operations against Shiite rebel strongholds to enable relief agencies to reach civilians trapped in the fighting areas.

The ceasefire will be active as of 9:00 pm (1800 GMT), the country's Supreme Security Committee said in a statement.

It said the ceasefire was ordered in response to appeals from international and local aid agencies as well as residents of Saada province, the scene of a massive military offensive by the rebels, who are known as Houthis.

The committee said the move was taken after the rebels had agreed to stop attacks against government troops and to clear landmines from roads.

A military source said earlier Friday that army troops have killed three prominent rebel field leaders and wounded another.

The source, quoted by the state news agency Saba, said the rebel leaders were killed Thursday when army units attacked rebel positions in al-Malahid district of the war-wracked Saada province, the scene of a massive military offensive on the rebels.

The military source identified the slain commanders as Jarallah Muhammed Ismail, Ali Abdu-Rabu Jabal and Abdul-Aziz al-Arimi and said a fourth rebel commander, Hussein Yahya Hanash, was wounded.

Army forces have been pounding rebel bases in Saada, which lies on the border with Saudi Arabia, since August 11. The offensive has included aerial, artillery and missile strikes on rebel strongholds in strategic heights overlooking the Saudi border.

Scores of insurgents, civilians and troops have been killed in the past two weeks. Around 150,000 people have been displaced.

Saba quoted the unnamed source as saying the army had begun using special force snipers to take down rebel fighters, resulting in "huge losses" for the guerillas.

Commandos were also waging gun battles late Thursday with rebel fighters hiding in houses in the old city of Saada, which lies near the identically named provincial capital of Saada, local officials told the German Press Agency dpa.

In the Dammaj area near Saada city, the army destroyed trucks carrying weapons and food for the rebels, who have been sporadically fighting the government since 2004, Saba said.

Authorities accused the Shiite group of seeking to restore the rule of the Zaydi royal family, known as the imams, who were toppled by a republican revolution in northern Yemen in 1962.

The Houthis said they are revolting against government corruption and the Yemeni alliance with the United States.

It was not possible to independently verify the army's reported successes as journalists are denied free access to Saada, about 240 kilometres north of the national capital, Sana'a.

On Thursday, the army reported progress in wiping out bases of the rebels and killing 11 insurgents as government forces destroyed several rebel mountain posts in the districts of al-Minzala, al- Hamazat and Nushur and captured five other posts in Dhu Sulaiman village.  dpa