|The opposition has warned that any more violence against demonstrators could scupper the GCC transition deal [AFP]
Vast crowds have taken to the streets across Yemen to demand the immediate resignation of Ali Abdullah Saleh, the president, rather than the phased handover of power envisaged by a Gulf Arab plan expected to be signed on Sunday.
On Siteen Street, the largest road in Sanaa, the capital, 100,000 anti-government protesters flooded a 5km stretch to mark a "Friday of Loyalty to the Martyrs" commemorating the deaths of at least 142 protesters killed in the past three months.
During a Muslim prayer service, an imam read out a list of those killed in the protests.
"Enough blood, enough killing, just leave, leave, leave," the imam said during the sermon. "You have to submit to the people's demands."
Tens of thousands of people also gathered in the city in a pro-Saleh rally to mark a "Friday of Constitutional Legitimacy".
Waving flags and pictures of the president, they shouted: "The people want Ali Abdullah Saleh."
The demonstrations came as the AP news agency reported that Yemeni plainclothes police had opened fire on Friday on protesters calling for Saleh's ousting in a western port city.
Five protesters were wounded in the shooting in Hodeida on the Red Sea, and both sides then hurled stones at each other, witnesses said.
A deal brokered by the Gulf Co-operation Council to end the crisis by easing Saleh out within a month is expected to be signed on Sunday in Riyadh, the Saudi capital.
The deal would give Saleh and his family and aides immunity from prosecution.
It provides for Saleh to appoint a prime minister from the opposition, who would then form a transition government ahead of a presidential election two months after his resignation.
But a sizeable section of protesters are against giving Saleh one month to quit, fearing it may offer time for the potential sabotaging of the deal.
Saleh also appeared to raise a potential problem on Thursday when he told the broadcaster Russia Today that he objected to the presence of Qatari representatives.
"We will have reservations about signing if representatives of Qatar are present among the Gulf foreign ministers," Saleh told Russia Today.
"[Qatar] is involved in a conspiracy, not just against Yemen but against all Arab countries."
He singled out Al Jazeera, which is based in Qatar, as having provoked past protests.
Washington and neighbouring oil producer Saudi Arabia want the standoff resolved to avert a descent into more bloodshed in the Arabian Peninsula state that could offer more room for a Yemen-based al-Qaeda wing to operate.
The balance of power has tipped against Saleh, long a key ally of the West against al-Qaeda, after weeks of violence, military defections and political reversals.
Whoever leads Yemen's transitional government will not only struggle to quash an aggressive al-Qaeda branch, which has tried to hit US and Saudi targets, but also inherit simmering rebellions in the north and south of the country.