BOGOTA - Colombia's incumbent President Juan Manuel Santos won a second four-year term in the presidential election runoff held Sunday.

Colombia's National Civil Registry said on its website that Santos beat his rival Oscar Ivan Zuluaga with 50.89 percent of the vote against 45.06 percent.

The National Electoral Council said that 15,698,505 out of 32, 975,158 eligible voters participated in the presidential runoff elections, placing the turnout rate at 47.60 percent.

Santos' victory came as a relief to his supporters backing peace talks with the leftist rebels rather than a war that would be an option for the opposition candidate Zuluaga.

In a victory speech, Santos thanked Colombians for their support and highlighted peace as an essential condition for the country's development, as his followers shouting "peace, peace, Colombia wants peace!".

Santos sent a message to the two largest anti-government guerrilla groups, the Revolutionary Armed Forces of Colombia (FARC) and the National Liberation Army (ELN), saying that he would dedicate all the energies of his government to end the decades-long conflict.

"This is the beginning of a new Colombia in peace with itself," said the reelected president, calling on all his compatriots to make painstaking efforts toward lasting peace in the country.

Santos, 62, from the ruling Social Party of National Unity, presented himself as the candidate of peace.

His rival Oscar Ivan Zuluaga conceded his defeat, saying if he had been elected, he would have provisionally suspended peace talks with FARC until it agreed to an unilateral ceasefire.

Santos initiated negotiations with the FARC in Havana in November 2012 in a bid to end the 50-year-old conflict in Colombia that had killed over 200,000.

The president said on Wednesday that his government was exploring the possibility of launching peace talks with the country's second largest rebel group ELN.