Bogota, June 16 (NNN-RHC) -- Colombia's incumbent President Juan Manuel Santos has won a second four-year term in the presidential election runoff held Sunday.

On its official website, the country's National Civil Registry stated that Santos won the second round, with 50.89 percent of votes cast (7,759,204 ballots), compared to 45.06 percent of the votes for the opposition candidate, Oscar Ivan Zuluaga.

The National Civil Registry said 99 percent of the votes have been counted.

Official data show more than 32 million Colombians were registered to vote in the country's 32 departments or provinces, with the installation of 1,890 ballot stations across the country.

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

Colombians went to the polling stations amid tight security. A total of 437,000 soldiers and police officers were sent out to secure the security of the runoff election, said Colombia's Defense Minister, Juan Carlos Pinzon, at a press conference held in Bogota, Sunday.

In the first round of voting held on May 25, Oscar Ivan Zuluaga, candidate of Colombia's conservative Democratic Center Party, won with 29.25 percent of the votes, while the incumbent, Juan Manuel Santos, received 25.69 percent, according to Colombia's National Electoral Council (CNE).