Guinea's veteran opposition politician Alpha Conde was declared the winner of its first free presidential election after a tense day of violent clashes as his rival's camp claimed voting fraud.

The 72-year-old Conde won 52.52 percent of the votes in the run-off election against former prime minister Cellou Dalein Diallo who garnered 47.48 percent, the Independent National Electoral Commission (CENI) announced late Monday.

Diallo, who had insisted he would not accept the election results before the investigation of "massive fraud at all levels" called on his supporters to remain calm, avoid provocation and violence of any nature."

He said he would prove to the Supreme Court that they were "riddled with irregularities and fraud." The court has to confirm the election results.

"If it agrees to objectively examine our claims, I hope to be rightfully declared the winner," he said.

Violence flared earlier in the day in Diallo's strongholds in the capital, as his supporters clashed with security forces, leaving at least one dead and dozens injured according to a police source.

In those same suburbs, gunshots were heard after the announcement of the results, as security forces maintained a strong presence there. But no deaths or injuries have been reported.

Meanwhile, suburbs backing Conde celebrated the news of his victory in what is the west African country's first democratic vote since independence from France in 1958.

As the country absorbed the news, UN Secretary General Ban Ki-moon urged Guineans to "accept the results of the elections and to resolve any difference through legal means."

After the official results were announced Conde reached out to Diallo.

"The time has come to join hands," he said.

"I extend a brotherly hand to build a united and prosperous Guinea," he added, saying he would be "the president of change to benefit all, the president of national reconciliation and progress."

Electoral commission chairman Siaka Sangare said Monday night that CENI had received 31 complaints of which 28 came from Diallo's UFDG.

He has already said that all claims of fraud had been treated "with the maximum attention" and suggested candidates go to the Supreme Court if they were still not satisfied.

Despite the November 7 vote being hailed as peaceful both locally and abroad, observers raised fears of further violence after the release of results, and the campaign leading to the run-off was marred by ethnic clashes.

With Conde coming from the Malinke group and Diallo from the Fulani, the election pitted the country's two ethnic minorities against each other.

The country has been presided over by a transitional military-led government since a coup in December 2008 followed the death of president Lansana Conte, who held power for 24 years.

The country plunged into further crisis under the military junta when troops massacred more 150 protesters opposed to coup leader Captain Moussa Dadis Camara at a rally in a Conakry stadium in September 2009.

Interim president General Sekouba Konate, led Guinea to its first-ever democratic election, with a first round taking place on June 27 from which Diallo emerged with 43 percent of the vote while Conde garnered 18 percent.

Despite Diallo's apparent commanding lead, alliances and ethnic voting allowed Conde to gain ground.

The extremely poor country, which is nevertheless rich in bauxite and iron-ore, is counting on a new government for economic revival in a nation where most people live without running water and electricity.