Yemeni demonstrators wave their national flags and hold banners during a demonstration against the government, in Sanaa, Yemen, Thursday, Feb. 3, 2011. Image Credit: AP

San'aa: More than 20,000 Yemenis filled the streets of Sana'a on Thursday for a "Day of Rage" rally, demanding a change in government and saying President Ali Abdullah Saleh's offer to step down in 2013 was not enough.

Further anti-government protests were expected across Yemen, which Saleh has ruled for over three decades, and supporters of the president were driving around the capital urging Yemenis over loudspeakers to join pro-government counterdemonstrations.

But by early morning, anti-government protesters had already gathered the largest crowd since a wave of protests hit the state two weeks ago, inspired by protests that toppled Tunisia's ruler and threaten Egypt's president.

"The people want regime change," protesters shouted as they gathered outside Sana'a University. "No to corruption, no to dictatorship."

Saleh, eyeing the unrest spreading in the Arab world, indicated on Wednesday he would leave office when his term ends in 2013, and promised his son would not take over the reins of government, among a host of other political concessions.

It was his boldest gambit yet to stave off turmoil in Yemen, a key ally of the United States against Al Qaida, as he sought to avert a showdown with the opposition that might risk sparking an Egypt-style uprising in the deeply impoverished state.

Wael Mansour, an organiser of the Thursday rally, said Yemenis were not satisfied with Saleh's concessions.

"Today will bring more, fresh pressure on President Saleh, who will have to present further concessions to the opposition," he said, without specifying what those concessions might be.