Keiko Fujimori and Pedro Pablo Kuczynski Reuters

After Sunday's vote, Peru's National Office for Electoral Processes (ONPE) declared that centrist Keiko Fujimori, daughter of the jailed former President Alberto Fujimori, leads in the ten presidential candidates with 39.18% of the vote.

As none has emerged with the necessary 50% vote share, there should be a run-off between the top two, as per Peruvian electoral rules. The run-off has been slated for 5 June.

The nearest contender is Pedro Pablo Kuczynski with 24.25% share percent, ahead of leftwing candidate Veronika Mendoza, with 16.25%. The results reflected 40% of the vote, which had been counted.

As per unofficial surveys considering 100% of votes, Kuczynski has 21.5%, Mendoza has 18.7% while 39.6% goes to Fujimori.

The 40-year old Fujimori who acted as first lady following her parents' turbulent separation during her father's authoritarian presidency, centered her campaign on continued economic growth and security, mirroring key policies of her father.

Kuczynski – also known as PPK – campaigned on liberal economic policies and spoke often about the need to clean up widespread corruption.

The 77-year old served as a central bank official and minister in former governments following a long tenure on Wall Street.

Mendoza, a 35-year old half-French psychologist and politician, fluent in Quechua, said she would change the constitution, implemented in 1993 during Alberto Fujimori's regime, and increase government involvement in Peru's mining-centered economy.

The results come following a tumultuous campaign including months of indecision regarding candidates that would run for the country's top executive job.

Partial official results Sunday night indicate that Peruvians will return to ballots in June to choose between Fujimori and Kuczynski as their next president.

The ONPE said a full result of ballot results should be released on Monday.

For the first time, electronic voting was introduced in several smaller Lima and Callao districts. Electoral officials were at hand to explain voting procedures to voters.