(CNN) -- Fraud has forced Haiti's election council to delay results of a highly anticipated runoff intended to decide the next leader of the troubled Caribbean nation.
Results were supposed to have been announced Thursday. But the Provisional Election Council asked for four more days and will post preliminary results on Monday instead. Final results are not expected until April 16.
The agency said "a high level of fraud and irregularities of various kinds has been detected in the tabulation of votes."
The election pitted former first lady Mirlande Manigat, 70, against bad-boy musician Michel Martelly, 50. The initial election in late November ended in controversy when Jude Celestin, the government-backed candidate, placed second after Manigat.
Charges of massive vote-rigging and other irregularities surfaced and protests erupted for several days on the streets of Port-au-Prince and other cities. In January, a vote review disqualified Celestin and prompted the runoff between Manigat and Martelly. Both candidates have expressed confidence in their showing.
The second round of elections unfolded peacefully for the most part amid concerns that the return of former President Jean-Bertrand Aristide, a polarizing figure in Haiti, would disrupt the vote. Aristide arrived in Haiti two days before the runoff but has kept a low profile so far and did not endorse a candidate.
Haiti's next leader will inherit a job laden with challenges as the impoverished country struggles to rebuild after last year's devastating earthquake and a cholera epidemic.