​Poll watchdog Konta Daya received at least 4,566 reports of election violations, most of which were caused by errors in automated counting machines (ACMs).

According to the group, these cases of ACM error included paper jams, mismatch of actual votes against voter-verified paper audit trail (VVPAT) results, and overvoting due to slight smudges or markings on the ballot, with the last two also resulting in voter disenfranchisement.

Out of 4,566 complaints reported, Kontra Daya--in partnership with Vote Report PH--said it was able to verify 566 incidents.

The majority of election violation reports are ACM erros, at 53.9 percent. It was followed by illegal campaigning at 7.8 percent and disenfranchisement at 7.2 percent.

"Illegal campaigning reports reveal the display and distribution of campaign materials including sample ballots near polling precincts, among others," Kontra Daya said.

"Voters also reported cases of disenfranchisement when they did not find their names on the voter’s list of their respective precincts," it added.

Some voters also complained about the over-sensitivity of machines that have mistakenly tagged some ballots as overvoting despite careful shading within the circle and the right number of allowable candidates.

Other violations were cases of red-tagging, non-compliance of board of electoral inspectors or electoral boards, vote-buying, and selling, election violence, black propaganda, tampered ballots and election harassment.

​"Compared to previous elections, this year we​'ve seen a spike in reports of overvoting. The Co​mmission on Elections (Comelec)'s inaction on these issues will lead to more voter disenfranchisement and greater risk of election fraud,” Danilo Arao, convenor of Kontra Daya​, said.