|Saleh told supporters at a rally near his office that their presence meant legitimacy for his rule [Reuters]
Yemenis have turned out in large numbers across the country to call on their long-serving president to immediately step down, while pro-government supporters rallied in the capital Sanaa.
Hundreds of thousands held an anti-regime protest after Friday prayers outside Sanaa University.
Protests demanding Ali Abdullah Saleh's ouster were also held in southern Taiz city, the port of Aden and eastern Hadramawt province.
But Saleh, in power since 1978, told tens of thousands of supporters gathered near his presidential office that their huge number gave him legitimacy and was a "rejection of chaos".
Saleh called on the opposition to join talks to ensure stability returns to the Arab worlds's impoverished nation where protesters are demanding change for the better.
"We call on the opposition to consult their consciences and come to dialogue and reach an agreement for security and stability of the country," Saleh said in an address to his supporters on Friday.
"These crowds are a clear message to those inside and outside the country ... on constitutional legitimacy."
Saleh, who has warned of civil war and the break-up of Yemen if he is forced to step aside before organising parliamentary and presidential elections over the next year, branded the opposition liars and "bandits".
He made an appeal to religious sensitivities when he said the opposition should stop the mixing of unrelated men and women among Sanaa protesters.
"I call on them to prevent mixing that is against Islamic sharia law outside Sanaa University," he said.
The loyalists raised banners with slogans such as "the people want Ali Abdullah Saleh".
"The opposition are bandits and saboteurs. They refuse dialogue because they want to take power by coup not by ballot box," said pro-Saleh protester Farid Toshi.
Opposition groups, protesting for months, have called for Saleh to step down over the country's lack of freedoms and extreme poverty.
The protests, inspired by the uprisings in Tunisia and Egypt, began when Saleh was already struggling to quell a separatist rebellion in the south and cement a truce with Shia Muslim rebels in the north.
Activists have distributed leaflets calling on people to stop paying taxes, electricity and other bills to the government in a campaign of civil disobedience to force Saleh out.
Strikes in schools and government offices began in the southern city of Aden last week.
Electricity supply was hit in cities including Sanaa, Taiz, Hudaida and Ibb after tribesmen attacked a main power plant, an official said, accusing them of acting on behalf of opposition parties.
Thirteen protesters were hurt in Taiz when Saleh loyalists opened fire on some of tens of thousands who took to the streets after Friday prayers, witnesses said.
The opposition has set a two-week deadline for the president to step aside, rejecting a Saudi-brokered, Gulf Co-operation Council-backed initiative to end the country's political turmoil.
"We have renewed our emphasis on the need for speeding the process of [Saleh] standing down within two weeks. Therefore we will not go to Riyadh [the Saudi capital]," Mohammed al-Mutawakkil, a prominent opposition leader, said on Thursday.
Meanwhile, Yemeni religious scholars and tribal leaders have said they would support the demands of the youth revolution and called on Saleh to step down immediately.
In a statement issued late on Thursday in Sanaa, they said the peaceful demands of protesters should be met and urged "the immediate stepping down of the President of the Republic and the dismissal of all his relatives from the military and security apparatus of the state".
Diplomatic sources say talks in recent weeks on resolving the crisis have stalled over Saleh's insistence on immunity from prosecution for himself and his family.
Jamila Ali Rajaa, a former adviser to the Yemeni foreign ministry, told Al Jazeera there is a "small possibility" that the unrest could be resolved through dialogue.
At least 116 people have died in protests which security forces have attacked with live fire and tear gas.
Saudi and Western allies of Yemen like the US fear that a prolonged standoff in Yemen could ignite clashes between rival military units and cause chaos that would benefit an active al-Qaeda wing operating in the mountainous country.
Source: Al Jazeera and agencies