Military sources in Yemen say dozens of people have been killed in new clashes between government troops and Shi'ite rebels.
The sources say the fighting took place Sunday in the northern provinces of Omran and Saada.
Yemen's SABA news agency reports that 30 rebels were killed in the area of al-Shaqra'a and dozens more killed around Harf Sufyan and Almalaheedh.
There was no independent confirmation of the reports.
On Saturday, Yemeni President Ali Abdulalh Saleh said his army is prepared to fight the Shi'ite rebels for years if necessary.
He also called on the rebels to accept a government-proposed cease-fire.
Two other cease-fires announced in the past month have lasted only a few hours. Each side blamed the other for the resumption of fighting.
Last week, the United Nations refugee agency warned that the humanitarian situation in northern Yemen is dire, with more refugees arriving in displaced persons' camps every day.
The aid group Oxfam has warned that Yemen faces a humanitarian crisis unless steps are taking to halt the fighting.
In August, President Saleh began an air and ground offensive against rebels from the Shi'ite Zaidi sect, also known as al-Houthis.
Zaidis dominate northwestern Yemen, but are a minority in the country as a whole. Since 2004, the rebels have been fighting against what they say is government oppression.
Intermittent clashes over the past five years have displaced an estimated 150,000 people.
Some information for this report was provided by AFP.