Kyrgyzstan's former prime minister, Almazbek Atambayev, is poised to become president after taking a commanding lead in the country's first presidential election since last year's bloody uprising ousted the government.

With about 99 percent of the first-round votes counted, official results have the Moscow-backed Mr. Atambayev far ahead of 15 other candidates, with 63 percent of the vote. That is enough for an outright majority and avoids the need for a second-round runoff. Mr. Atambayev stepped down as prime minister last month to run for the presidency.

Other candidates, including former boxer Kachimbek Tashiyev and Adakhan Madumarov, each received less than 15 percent of the vote and are accusing officials of fabricating the results. Monitors from the Organization for Security and Cooperation in Europe noted voting irregularities, including people voting more than once, ballot-box stuffing and authorities refusing to let voters register.

Despite the problems, international observers say they are “cautiously optimistic” about the future of democracy in Kyrgyzstan. But candidates Tashiyev and Madumarov both say they will not accept the election results and have warned of mass protests.

Mr. Atambayev says he will seek a path of consensus in the country.

Kyrgyzstan hosts both U.S. and Russian military bases and is a crucial hub for NATO operations in Afghanistan. Some of the candidates have promised to respect the U.S. base lease, which expires in 2014.

Sunday's election comes a year after nationwide protests against corruption and poverty led to the ouster of president Kurmanbek Bakiyev. His overthrow sparked violence between ethnic Kyrgyz and ethnic Uzbeks, leaving hundreds dead and entire towns in ruins.

Since then, Kyrgyzstan has been run by Roza Otunbayeva, Central Asia's first woman president. She plans to step down at the end of her term on December 31, becoming the first Central Asian leader to step down voluntarily since the five former Soviet republics in the region won independence at the collapse of the Soviet Union 20 years ago.