Medical officials say at least one person was killed and many more wounded in clashes between Yemeni protesters and security forces in the city of Taiz and the capital Sanaa on Saturday.
In Taiz, the trouble flared throughout the day and into the evening. Shots were fired and water canons were used.
A doctor said about 30 people were hurt by batons and rocks, with a further 500 suffering teargas inhalation.
In Sanaa ambulances ferried the injured to hospital. They had been trying the swell the numbers in their protest camp.
Witnesses say dozens were wounded when men in civilian clothes, believed to be security officers, opened fire. Again, teargas was also used.
President Saleh had initially accepted an offer from Saudi Arabia and other Gulf Arab states, to hold talks with the opposition about ending his 32 years of autocratic rule .
He then rejected that offer on Friday, telling supporters it was “belligerent intervention”.