Local media reports said that four people suffered knife-related injuries with one in serious condition after two groups of opposing sides clashed outside the country's consulate.
A police spokeswoman said she could give no further details on the number of the wounded or the nature of their injuries.
Turkish voters living abroad flocked to the ballot boxes at customs gates to cast their votes on Monday, the first day of voting on the constitutional amendment package, amid intensive efforts by European media and politicians to interfere in the election process by promoting "No" votes.
