Observed by: Mr. Alaa Isam
Police who had been trying to keep the sides apart locked several thousand fleeing protesters inside the Sanaa University campus near where they had been holding their rally. Five people were wounded in the melee, an opposition source said.
"Hey Ali, get out, get out!" anti-government protesters shouted, referring to President Ali Abdullah Saleh, a U.S. ally against al Qaeda's resurgent Yemen-based wing who has been in power for over 30 years. "There is no solution except to leave."
Protests in impoverished Yemen have gained momentum in recent weeks, sometimes drawing tens of thousands of people, but have become more and more violent since Friday with clashes between protesters and police or pro-government groups.
The threat of turmoil in Yemen, already teetering on the brink of failed statehood, has pushed Saleh to offer significant concessions, including a pledge to step down in 2013 and an invitation to the opposition for a reconciliation dialogue.
Analysts have said Yemen is not yet at the point of an Egypt-style revolt, and any upheaval would likely unfold more slowly, and perhaps with more bloodshed, in a heavily armed country where tribal allegiances run strong.
"With our blood, we sacrifice for you Ali!" Saleh supporters chanted in Sanaa before violence erupted. Some of the several hundred loyalists who gathered held pictures of the man who has ruled Yemen for 32 years, and they waved Yemeni flags.
CLASHES IN TAIZ
Another 12 people were reported hurt south of Sanaa, where police fired shots into the air as hundreds of anti-government demonstrators clashed with Saleh supporters, witnesses said.
But police were unable to control the crowds in the agro-industrial town of Taiz, where thousands of protesters had held an overnight rally.
In the south, where the government faces al Qaeda militants and rising secessionist sentiment, hundreds of anti-government protesters marched in the port city of Aden, some throwing rocks and clashing with police. Security forces used batons to disperse the marchers, arresting five people, residents said.
The disturbances occurred while Saleh and a main opposition group were preparing for talks that the government hoped would help avert an Egypt-style revolt.
Saleh, under pressure from the United States to make good on promised reforms, postponed Sunday a U.S. trip scheduled for later in the month due to regional conditions.
Human Rights Watch criticised Yemeni police for what it described as unnecessary brutality against demonstrators, including the use of electroshock tasers.
"Without provocation, government security forces brutally beat and tasered peaceful demonstrators," said Sarah Leah Whitson, a regional director at the U.S.-based rights group
Amnesty International called on Yemen "to rein in its security forces immediately and stop excessive use of force."
Police have generally stayed out of the fray in Sanaa, while crackdowns have been stronger outside the capital.
But Sunday, police broke up an anti-government march to the presidential palace, sparking clashes in which police beat protesters with batons and protesters hurled rocks at police, witnesses said. Several journalists were briefly detained.
Even as it faces popular unrest, Yemen is also struggling to cement a cease-fire with Shi'ite Muslim insurgents in the north.
(Additional reporting by Mohammed Mokhashef in Aden; Writing by Erika Solomon; editing by Cynthia Johnston and Alastair Macdonald)