Tens of thousands of protesters turned out in cities across Yemen on Friday to call for the ouster of President Ali Abdullah Saleh in a remarkable show of determination after six months of demonstrations and armed clashes that have failed to topple the embattled leader.

As an army unit that has sided with the protesters provided protection and prevented a group of Saleh supporters from praying near the site of the protest, demonstrators in the capital, Sanaa, chanted: “We won’t talk. We won’t negotiate. Victory is near!”

On the other side of the city, a smaller group of Saleh backers rallied in support of the president.

Six months of mass protests have posed an unprecedented challenge to Saleh’s 33-year rule, although the movement seeking to oust him has reached a stalemate with the government.

Saleh remains in power despite spending nearly two months outside the country for treatment of wounds, including severe burns, that he suffered in a bomb attack on his palace mosque. He has been able to hold on to power largely because of his allies in the security forces. His son Ahmed commands the elite Republican Guard.

Saleh’s aides insist that he will return to Yemen after completing medical treatment in neighboring Saudi Arabia.

Meanwhile, security across the country has broken down, with armed tribesmen battling security forces in a number of places and al-Qaeda-linked militants taking control of towns in the country’s restive south.

On Thursday, clashes between Yemeni soldiers and armed tribesmen in a mountainous region north of the capital left at least 40 people dead, according to the military.

Friday’s protests were the last before the month of Ramadan, when Muslims fast from dawn to dusk. It remains unclear what effect the observances will have on the protesters’ ability to mobilize large numbers.

A preacher who addressed marchers in the town of Ibb after Friday prayers suggested that the holy month could bring a breakthrough. “We expect that during Ramadan, our brothers in the Republican Guard and Central Security will join the revolutionaries to finish toppling the rest of the regime,” Abdel-Salam al-Khadeiri said.

Large protests were also held Friday in Taiz, Hudaydah, Mukalla and other places.

— Associated Press

Yemeni men inspect the scene where a suicide bomber driving a pickup truck targeted army personnel carriers at the entrance to a military camp in the main southern city of Aden, killing seven people Sunday. (-/AFP/GETTY IMAGES)