Six people, one of them identified as Osman Sarigun, allegedly attacked Kemal Kilicdaroglu, head of the Republican People's Party (CHP), on Sunday when he was attending a Turkish soldier's funeral.
Several protesters threw punches at Republican People's Party leader Kemal Kilicdaroglu at the funeral outside Ankara on Sunday. "They are not genuine Muslims".
"It's wrong to blame the interior ministry for such incidents while partnering with the political arm of the PKK at the same time", Soylu added, saying Kilicdaroglu's party was trying to make political gains from the attack.
The leader added that he was not saddened by the attack and that it would not deter him from defending law and justice.
"Legal action has been launched against the culprits of the incident", the Ankara governor's office said in a statement.
Turkish President Tayyip Erdogan, whose AK Party wants the election results annulled in Istanbul, had repeatedly warned during last month's campaign that PKK members were among the CHP's list of candidates.
Turkey's High Election Board has not yet ruled out the two AKP petitions to cancel and re-run the vote in Istanbul but the CHP's new Istanbul mayor Ekrem Imamoglu took up his post on Wednesday.
A recount by election authorities determined that Mr Imamoglu had won the election by around 13,000 votes, granting him his mandate.
The party held Interior Minister Suleyman Soylu responsible for the attack because the minister said past year he had ordered the governors not to let CHP members to join martrys' funerals.
The politician was not hurt, party officials said.
Shortly after the attack, Soylu said it could not be accepted.