At least two people have been confirmed dead and hundreds more injured after Yemeni security forces fired at protesters in the southern flash-point city of Taiz.
About 30 people are reportedly in critical condition.
Hospital sources said more than 100 people were hurt by live bullets while another 1,000 were suffering from tear gas inhalation during Friday's protests.
Witnesses reported gunshots near the site of an anti-government sit-in in Taiz.
The protesters had been carrying the bodies of five people killed earlier in the week to their gravesites when they ran into security forces.
The fresh clashes on Friday between anti-government protesters and the police came as Ali Abdullah Saleh, the Yemeni president, rejected a new deal for him to leave after 32 years in power.
Some 21 people have died in clashes this week in Taiz and the Red Sea port of Hudaida.
Rival demonstrations
In the port city of Aden, once the capital of an independent south, thousands of anti-government protesters gathered peacefully and in Hudaida, some 15,000 gathered to mourn protester deaths and demand Saleh step down.
And in Sanaa, Yemen's capital, tens of thousands of people assembled for rival demonstrations - with some demanding Saleh's dismissal and others showing their support.
Police and army units were deployed to prevent any friction between the two sides.
Al Jazeera's special correspondent in Sanaa, who is not being named for security reasons, said the pro-Saleh demonstrations in front of the presidential palace on Friday were very similar to those seen in recent weeks.
"It is very difficult for Al Jazeera to go anywhere near those protests. We have to rely on what we are seeing on Yemen state television ... we can see the mass crowds turning out week after week," the correspondent said.
"But according to some people in Change Square, where the rival protests are, those people are not there because they genuinely support Saleh but because they are either government forces dressed in civilian clothes or are being paid by the ruling party."
Our correspondent said such accusations have been going around for weeks, with pro-democracy protesters saying that the more Saleh loses control, the more he is seen firing on anti-government protesters and also trying to ensure there are large crowds at his rallies.
Protesters have been calling since January for the departure of Saleh, who has been in power since 1978.
Saleh initially accepted an offer by Saudi Arabia and other Gulf Arab states trying to broker an end to bloody protests and hold talks with the opposition.
But he later rejected the plan for his exit in a speech broadcast on state television on Friday.
PHOTO CAPTION
Yemeni President Ali Abdullah Saleh delivers a speech to his supporters in Sanaa on April 1, 2011.
Al-Jazeera