Yemen's President Ali Abdullah Saleh has addressed large crowds in the capital, Sanaa, denouncing protesters and vowing to stay in office.
Mr Saleh, who has faced more than two months of protests, said the crowds gave him legitimacy.
There were rival anti-government rallies in Sanaa and in other towns, with clashes reported in the southern flashpoint town of Taiz.
Protesters want Mr Saleh to step down immediately after 32 years in office.
They have rejected an offer for negotiations to be held in Riyadh, Saudi Arabia, on a transfer of power.
Mr Saleh used Friday's rally to call for the opposition to enter into talks with him, portraying himself as the legitimate leader of Yemen.
"We call on the opposition to consult their consciences and come to dialogue and reach an agreement for security and stability of the country," Mr Saleh said.
"These crowds are a clear message to those inside and outside the country... on constitutional legitimacy," Reuters news agency reported him as saying.
However, even as the president spoke huge crowds were gathered to oppose his continued tenure in office.
One cleric said at a rally near Sanaa University: "It's only a matter of days before this regime is over. This revolution cannot be defeated. Our aim to bring down corrupt family rule."
Protesters also want Mr Saleh to face prosecution for what they say are crimes committed during three decades in office.
On Friday, several influential tribal and religious leaders switched sides, weakening the president further, says a BBC correspondent currently in Sanaa.
While the political bickering goes on Yemen is falling apart, our correspondent adds, with the economy in ruins and oil production halved.
Diplomats say Mr Saleh is spending millions of dollars on staging pro-government rallies.
In response opposition activists are trying to launch a nationwide public disobedience campaign and are calling on people to stop paying their utility bills and taxes.
Gas and electricity shortages are already widespread, our correspondent says.