Supporters of presidential candidate Guillermo Lasso protest near the Electoral National Council in Quito, Ecuador, Tuesday, April 4, 2017. Juan Pablo Pozo, president of the electoral council, announced the razor-thin election win by Moreno in a nationwide broadcast on radio and television. He said the results were “official, irreversible” with 99.65 percent of the votes counted. Lasso is demanding a recount. (AP Photo/Dolores Ochoa)

QUITO, Ecuador - Conservative candidate Guillermo Lasso says his campaign for the presidency of Ecuador detected irregularities at almost 2,000 polling tables where his opponent handily won in Sunday's presidential runoff.

Lasso, in a press conference Wednesday, presented the strongest argument yet backing up his claims that ruling-party candidate Lenin Moreno won the election through fraud.

The Lasso campaign said it detected irregularities such as missing signatures, inverted results and incorrect tallies at 1,795 of the almost 40,000 voting acts processed nationwide. Those polling places together represent about 600,000 votes, more than double Moreno's margin of victory. It presented three such examples and said it would dispute results at the voting centres, some of which Moreno won by a 4-to-1 margin.

"Without a doubt there was fraud," Lasso said, standing before boxes of voting acts he said were scanned by campaign poll observers on election night and will form the basis of their challenge.

Moreno's Alianza Pais party said it would support a revision of the voting acts in question by election authorities.

"There shouldn't be the smallest shadow of doubt" over the election results, said Doris Soliz, executive secretary of the party.

Hundreds of Lasso supporters gathered Tuesday night outside the National Electoral Council's headquarters in Quito for the third straight night of mostly peaceful protests that contrasted with the more unruly behaviour seen on election night, when supporters crashed through metal barricades in Quito and scuffled with riot police in several cities. On Thursday, some 200 supporters remained outside the Quito headquarters.

Electoral authorities said if necessary they will recount votes at polling centres where results are formally challenged, and dismissed as "slanderous" accusations of discrepancies between what poll observers witnessed and the voting acts uploaded to the National Electoral Council's system.

"Some political actors are talking of fraud, but if there was any, it was moral fraud due to so much lying," said National Electoral Council President Juan Pablo Pozo.

Authorities have 10 days to resolve any disputes. Amid the continued uncertainty, Roman Catholic bishops issued a statement Wednesday calling for calm and unity, saying that the country's peacefulness is in danger.

News from © The Associated Press, 2017