At polling stations in Modi'in Illit, Jerusalem, Bnei Ayish, and Nahariya, suspicions of voter impersonation arose after voters arrived to polls only to be told that they had already voted.
The Israel Police said that following the complaints, an investigation into the cases was opened to clarify the circumstances.
A 22-year-old young man violating the peace near polls in Deir el-Assad, refusing police requests to cease and desist from his actions, was arrested for questioning after attacking police at the scene.
Earlier in the day, police at various locations around the country dealt with local public-order violations and attempts to distribute ballot slips to voters from outside the polls to vote with.
Police Chief Deputy Moti Cohen arrived this morning to the southern district of the city of Be'er Sheva, reviewed preparations in the area and noted: "Knesset election day is a holiday for Israeli democracy. Your role as police on this important and significant day is to maintain the proper democratic process and the purity of the elections, as well as maintaining security and public order.
"Beyond all routine tasks, our ultimate goal is to enable free voting by all Israeli citizens without interruption. So far, it's clear that police estimates provide a proper and appropriate response to the various scenarios. We must remember that this is a day of vacation and give great attention to the hundreds of thousands of citizens visiting the tourist sites. I wish all of us success in all the tasks and challenges that lie ahead for Israeli citizens and Israeli democracy," added Cohen.