SANAA: Yemeni President Ali Abdullah Saleh thanked thousands of supporters gathered near the presidential palace on Saturday for backing the constitution in a further sign he has no immediate plans to step down.

Weeks of protests across Yemen have brought Saleh's 32-year rule to the verge of collapse but the United States and neighbouring oil giant Saudi Arabia worry about who might succeed him in a country where al Qaeda militants flourish.

On Friday, tens of thousands of people, both for and against Saleh, took to the streets in Sanaa as negotiators struggled to revive talks to determine his fate.

"I salute you for your heroic stand and thank you for supporting constitutional legitimacy," Saleh told the crowd amid a sea of portraits of the president and banners supporting his continued rule.

Saleh, who has lost the support of many tribal, military and political backers, met representatives of several tribes, officials said, as he dug in against demands for his resignation.

In the western port of Hudaida, seven protesters were wounded when riot police used batons and teargas to disperse demonstrators calling for Saleh's resignation, residents said.

Thousands of anti-Saleh protesters holding a weeks-long sit-in outside Sanaa University marched towards the presidential palace but were turned back by security forces blocking the streets, residents said.

There were no clashes and the protesters returned to their tent city.

Protesters in Aden called for a general strike and acts of civil disobedience, closing down public transport and prompting many shops to close.

Troops fired in the air to disperse young people blocking roads, witnesses said.

"President Saleh and his entourage are still involved in their crimes and continue to refuse to understand the demands of the people," Yemen's opposition coalition said in a statement.

Saleh wants to stay on as president while new parliamentary and presidential elections are organised by the end of the year, an opposition source told Reuters on Tuesday.

Talks over his exit have stalled and Saudi authorities have deflected Yemeni government efforts to involve them in mediation.

Government sources said on Saturday that mediators were trying to relaunch the talks with opposition parties.

Rallies could spiral into violence at any time in the turbulent Arabian Peninsula state where more than half the 23 million population own a gun. Some 82 people have been killed so far, including 52 shot by snipers on March 18.

Rows often turn to bloodshed, from tribal clashes over dwindling water resources to army skirmishes with separatist militants in the south.

Washington has long regarded Saleh as a bulwark of stability who can keep al Qaeda from extending its foothold in Yemen, a country which many see as close to disintegration.

Saleh has talked of civil war if he steps down without ensuring power passes to "safe hands" and has warned against a coup after senior generals turned against him.