New Delhi, April 16 -- Keiko Fujimori, the conservative daughter of a disgraced former Peruvian president, and Roberto Sanchez, a nationalist congressman and former minister, were leading in the race for Peru's next president as ballots were being tallied on Wednesday for a fourth straight day.

Voting in Sunday's election had been extended into Monday after ballots were not delivered in time to polling stations.

With 90% of the ballots counted, official results on Wednesday showed Fujimori leading with 16.98% of the votes, while Sanchez had earned 12.04%. Trailing narrowly in third place was Rafael López Aliaga, the ultraconservative former mayor of Peru's capital, Lima, with 11.90%.

The election has been mired in logistical probl...