"As of 1 p.m. (11:00 GMT), 342 notifications of incidents related to the election process have been received. Thirty-six cases of vote buying have been registered," the ministry said in a statement.
According to the ministry, the majority of violations were in Kiev region and western Zakarpattia region.
The polls opened at 8.00 a.m. local time (06:00 GMT) and will close at 8.00 p.m. (18:00 GMT). Some 69 percent of all eligible voters are expected to cast their ballots.
Civil Control association, which is monitoring the elections in Ukraine, also registered mass violations and predicted low voter turnout, association co-chair Alexander Brod told RIA Novosti.
The elections are being observed by more than 1,500 international participants.
According to Brod, Ukraine is not capable of providing safety to the international observers.
The elections' vote count will be finished by November 4 and the results should be published within 5 days.