An anti-government protester throws back a tear gas canister fired by Yemeni forces during clashes in Taiz, Yemen, on Tuesday. Yemen Lens / Associated Press

SANAA, Yemen - Arab ambassadors were to meet Yemen opposition figures on Wednesday to urge them to join mediation talks as protesters around the country again demanded an end to President Ali Abdullah Saleh's 32-year rule.

World concerns over Yemen rose as the death toll mounted in weeks of anti-government protests.

The White House on Tuesday called for Yemen to resolve the political impasse and ensure the "safety and security" of people, calling on all sides to engage in a "constructive political dialogue".

Saleh has been a key US ally in the fight against the Yemen-based al-Qaida, but officials said the Obama administration has concluded that Saleh "must be eased out of office".

The Pentagon also said there were no plans to suspend US military aid to Yemen.

US Defense Secretary Robert Gates visited Saudi Arabia on Wednesday and was to discuss the unrest sweeping the region with King Abdullah, whose kingdom borders Yemen and is grappling with internal pressures of its own.

The turmoil in Yemen has killed more than 100 people, including the March 18 killings of 52 anti-government protesters by rooftop snipers in Sanaa.

On Monday security forces and armed men in civilian clothes fired on protesters in Taiz, south of Sanaa, and the Red Sea port of Hudaida, killing 21 people.

On Tuesday, security forces and armed men again attacked a crowd of tens of thousands of protesters in Taiz, residents said, and protesters responded by hurling rocks.

Around 300 were wounded in total, doctors said, most suffering from tear gas inhalation.

In London, British Foreign Secretary William Hague said he was appalled by the bloodshed and condemned the "indiscriminate violence" of security forces.

Italy urged Sanaa to "cease all forms of violence" against demonstrators and to open the way for "a constructive dialogue as soon as possible".

The European Union urged Saleh to begin a political transition "without delay".

UN Secretary-General Ban Ki-moon on Tuesday expressed strong concern over the dead and injured in the clashes.

The president himself has urged the opposition to join talks in Saudi Arabia to try to end violence on Tuesday, which was proposed by the Gulf Cooperation Council on Monday.

"I promise that we will make every effort to return things to normal through talks with rational people from the Joint Meetings Party," he said, referring to the opposition coalition.

Clashes between government backers and anti-government protesters continued on Tuesday in major provinces of Sanaa, Taiz, Al-Hodayda, Al-Bayda, Aden, Abyan, Ibb and Hadramout.

Reuters-Xinhua-AFP