Sana'a, Yemen  - Yemeni authorities late Friday declared a ceasefire in fighting with Shiite rebels in north-western areas in order to secure the passage of humanitarian aid to tens of thousands of people.

The truce, which begins at midnight and would last for the Eid al- Fetr holiday, was announced in response to appeals from international relief agencies, the official Saba news agency reported.

It did not give a specific time when the truce would end, but the Eid holiday ends September 28.

The Defence Ministry said in a statement the ceasefire was conditional on the rebels complying with five terms. It said the rebels should withdraw from areas they control and release soldiers they captured during the fighting.

Among the other conditions were the rebels' compliance with the constitution and their surrender of military equipment seized from the army.

This is the second truce declared by the government since the army launched it latest offensive on bases of the Houthis rebels on August 11. It is the latest flare-up in the fighting that has raged on and off since the Houthis revolt began in mid-2004.

On September 4, authorities announced a truce to allow access for humanitarian aid to civilians displaced by the fighting in the Saada and Amran provinces.

The first truce collapsed three hours after it took effect, and both sides traded blame for breaking it.

Hundreds of insurgents, troops and civilians have been killed and around 150,000 people were forced to leave their villages during the past five weeks, according to unofficial estimates.

Earlier Friday, UN Secretary General Ban Ki-moon called on the Yemeni government and the rebels to cease the fighting and allow humanitarian workers access to refugees.

The United States also called on the two parties to declare a 72- hour ceasefire.

"A 72-hour cease fire adhered to by both parties over the upcoming Eid holiday would provide international relief agencies an opportunity to provide emergency food and medical supplies to the tens of thousands of Yemeni citizens driven from their homes by the conflict," the US embassy in Sana'a said in a statement.

"The United States of America urges each party to publicly announce its intention to halt hostilities during this period, in recognition of their responsibilities under international law," it said.

Both sides have claimed to have inflicted heavy casualties over the last five weeks, but none of the claims have been independently verified, with the media denied access to the restive province.

Officials have said the offensive will only end when all insurgents surrender or are killed.

Authorities accuse the Shiite group of seeking to restore the rule of the Zaydi royal family, which was toppled by a republican revolution in 1962.

The Houthis say they are in revolt against government corruption and the Yemeni alliance with the United States. (dpa)