Four suspects have already been charged with vote buying, said Lt-General Nithithorn Jintakanon, spokesman of the election security centre,
Police are still conducting investigations to ensure the cases were not attempts by some candidates to frame rivals.
Nithithorn said the centre was alerted to 23 cases of ballot tearing, but most were unintentional as the ballots were torn by intoxicated voters or people suffering from dementia.
In one case a voter stumbled and accidentally tore a ballot, he said.
In another case, a voter marked the wrong box so he tore the ballot to ask for a new one, without knowing it was illegal to do so, Nithithorn said.
Interrogations of people who tore ballots did not find any cases in which they did so for political motivation, he added.
Two suspects were arrested for taking photos of ballots and six for selling alcoholic drinks on election day.
The centre will remain operating until Wednesday. It will monitor ballot counting and the transfer of ballot boxes to the Election Commission’s office in Bangkok, he said.
The centre will closely monitor Nonthaburi, Pathum Thani, Samut Prakan and Ratchaburi, where fierce competition has led to gun fights in the past, he said, adding that police are keeping a close eye on 20 other provinces where violence is possible.
Regarding allegations made by serial whistleblower Chuwit Kamolvisit that there were over 100 incidents of vote buying on Saturday night, Nithithorn said police had yet to investigate the allegations and that the information provided was one-sided.