Details added (first version posted at 16:07)
Protesters in Yemen vowed to escalate their protests following a call by President Ali Abdullah Saleh on Friday for early presidential elections to "prevent bloodshed" in the country, dpa reported.
A speaker addressed protesters gathered in the southern city of Taiz and called for a big march and escalation in protests for Sunday, which marks the 21st anniversary of the unification of Yemen.
The march will show "the real picture of the unity of the people against the tyrant," he said.
Yemeni activist Atiaf Al-Wazir said people believe that Saleh is trying to gain time in order to push the protesters to give up, especially as the summer heat becomes unbearable in the southern provinces.
"This is why there are calls for escalation, and now activists are trying to agree on a unified way to take the situation further across country," Al-Wazir told the German Press Agency dpa.
Saleh told tens of thousands of his supporters gathered in the capital Sana'a near the presidential palace that he is calling "for early presidential elections to prevent bloodshed, in a democratic way."
"You are our resistant people in front of the coup attempts, and treason," added Saleh, whose term ends in 2013.
Following his call, his supporters began chanting "The people want Ali Abdullah Saleh." Pro-Saleh protesters from across the country gathered in Sana'a to express their solidarity.
While Saleh was making his call, throughout the country tens of thousands of Yemenis had gathered to demand that he should step down.
"Once bitten, twice shy. And you have been bitten by the regime dozens of times," one imam told a crowd in Taiz.
In the capital Sana'a, thousands carried a huge banner that read: "People's Unity Friday - Get out" and chanting "The Yemeni people are one" and "Our demand is one - leave."
"The demands are clear, and early presidential elections are not among them," al-Wazir said.
"The main problem is that there is no trust between the people and the president. He changes his stance a lot. There is no guarantee that it will not change again one day before the elections," she added.
The protests come after US President Barack Obama urged Saleh to fulfill his commitment to a Gulf-brokered deal to transfer power to his deputy.
"President Saleh needs to follow through on his commitment to transfer power," Obama said Thursday in a speech about uprisings sweeping the Arab region.
Saleh, who has backtracked on his promises in the past, says he will have the deal signed on Sunday, after he rejected it one more time before.
"The initiative was originally rejected by protesters. And now after he said he will sign it on Sunday, he gives a different stance again," al-Wazir said.
Under the proposed deal, Saleh would be guaranteed immunity from prosecution and remained head of the ruling party. He would have transferred power to the vice president within 30 days of signing it. Presidential elections would then take place after 60 days.
With over 140 people killed since protests began in January, according to rights groups and medics, demonstrators have rejected the deal and called for Saleh to be brought to justice.