UN envoy to Yemen Jamal bin Omar urged the Yemeni people on Saturday to vote in the upcoming presidential election, as part of a deal to ease President Ali Abdullah Saleh out of office and pull the country back from political crisis.

Bin Omar, also a key mediator of the UN-backed power transfer deal brokered by neighboring oil-rich Gulf countries, arrived in Yemen's capital of Sanaa Saturday to oversee the process of the presidential polls scheduled on Feb. 21.

"I urge all Yemeni sides to elect the sole candidate, Vice President Abd-Rabbu Mansour Hadi, as new president for Yemen," bin Omar told reporters upon his arrival.

"The election will lead Yemen to a transitional period of two years, during which Hadi will hold a national dialogue with all Yemeni factions, form a national committee to rewrite the constitution and prepare for parliamentary elections," he said.

The polls will be watched by international observers, as Hadi promised to launch a national dialogue with the opposing groups to settle down differences after he takes power.

Bin Omar said that he will meet with all Yemeni parties, including Hadi, to review the implementation of the deal before reporting to the UN Security Council.

On Oct. 21, 2011, the UN Security Council passed Resolution 2014, backing the Gulf Cooperation Council (GCC) deal to end almost a year of protests against Saleh. On Nov. 23, Saleh, his ruling party and the opposition signed the deal in Saudi Arabia, under which Hadi will be elected to replace Saleh in early presidential election.

Saleh, currently in the United States for medical treatment, retains the title of honorary president until Feb. 21 and enjoys immunity from prosecution in accordance to the GCC deal.

However, anti-election riots raged in the restive northern province of Saada and several southern cities, where thousands of northern Shiite rebels and southern pro-separatism activists continued their rallies on Saturday to call for boycotting the vote, claiming that the deal did not meet their aspirations.