About 48 million people were eligible to vote in local elections in 81 provinces on Sunday, amid worries of rising unemployment, a slowing economy and allegations of corruption against the ruling AK party.
Five people were killed and 93 were wounded in election-related violence in the mainly Kurdish southeast of Turkey, the state news agency Anatolian said on Sunday.
Anita McNaught, Al Jazeera's correspondent in Istanbul, said: "There were tensions ahead of this vote, particularly in the southeast, with some clashes between the people helping the ruling AK party prepare their campaign, and the incumbents of the southeast protecting their patch.
"Five people were killed, but it was very local, and very small scale.
"Any other fighting has been localised, and not party-related, with some small level disputes between family members competing for the same small village role."
Erdogan, a former mayor of Istanbul, hopes to make gains in the mainly Kurdish southeast in what might prove a historic step towards solving a conflict weighing heavily on the country's economic and political development.
Residents in the southeast have historically supported the Kurdish Democratic Society party (DTP).
The government recently launched a Kurdish language TV station - the latest in several policy shifts considered more accommodating to Kurdish rights.
But Akin Birdal Istanbul, a DTP candidate, said the government initiatives would not sway DTP supporters.
He said: "The Kurdish people know that this is a tactic to get their vote.
"Up to now, a high price and pain was paid by us in order to gain our rights, so why is the government doing this now?"
Erdogan has said he would consider it a "failure" if his party won less in the provincial assemblies vote than in a 2007 general vote.
The AK party narrowly escaped being disbanded on charges of challenging Turkey's secular constitution last year.
Since Turkey won EU accession talks in 2005, critics have accused Erdogan of having lost his reformist spirit and say he is growing autocratic.
The opposition has been trying to capitalise on fallout from the global economic downturn as well as allegations of corruption against Erdogan's party that have forced two officials to step down.
The AK party, first elected in 2002, won general elections by a landslide 47 per cent in 2007.
In the last municipal elections in 2004, the party won 12 of 16 of Turkey's most important cities, including Ankara and Istanbul.