Four people have been killed in the run-up to Turkey’s election, staining what had been a largely peaceful election campaign and exposing electoral fault lines in the final days of the bitterly contested vote.

Tensions between supporters of the ruling Justice and Development Party (AKP) and the opposition Peoples’ Democratic Party (HDP) erupted into a firefight on June 14 in the mainly Kurdish town of Suruc near the Syrian border. The clash was a brutal reminder of how the battle to form the next Turkish government may come down to how Kurds, about 20% of the electorate, decide to vote.

Polls show support for the pro-Kurdish HDP hovering at 10%, the barrier it needs to clear to enter parliament. If it falls short, the AKP should easily win most of the legislature’s seats.

President Recep Tayyip Erdogan, who is running for re-election in a concurrent presidential poll, seems aware of the risk posed by the HDP, and last week an amateur video recording showed him ordering party officials to carry out “special work” on voter lists to keep the HDP below the threshold. The clear front-runner for the presidency, Erdogan has indicated he will not rule with a divided government and hinted in an interview with Bloomberg last month that the elections could be repeated to avoid one.