After two weeks of voting for Turkey's upcoming referendum on April 16, polling stations closed on Sunday at Turkish consulates in Berlin, Hamburg, Hanover, Frankfurt, Cologne, Düsseldorf, Münster, Karlsruhe and Mainz, as well as four other polling stations set up for the occasion.

Some 1.4 million Turkish voters live in Germany. According to Turkey's electoral commission, 49 percent of them had already cast their ballots by late Sunday.

Read more: What you need to know about the Turkish referendum

The Turkish-German electorate is an important demographic for President Recep Tayyip Erdogan, who is campaigning for a "yes" vote that would result in far-reaching changes to expand his powers.

Another 1.5 million members of Turkish diaspora communities in Austria, Switzerland, Denmark and France have also been able to cast their votes over the last fortnight of voting.

Too close to call

The sealed ballot boxes will now be flown to Ankara under supervision and transferred to the electoral commission where they will be opened and the counted in the presence of observers from the government and the opposition parties.

As the race enters the last week of campaigning, analysts believe the outcome is still too close to call.

Read more: Turkey's referendum runs deeper than 'Yes' or 'No'

EU bid back on the tabe

In a speech in the Aegean city of Izmir on Sunday, Erdogan described Europe as a "sick man", using the jibe that nineteenth century European politicians used to describe the decaying Ottoman Empire.

President Recep Tayyip Erdogan warned Sunday that Turkey's embattled bid to join the EU will be back "on the table" after next week's referendum on enhancing his powers, raising new doubts about the future of the membership drive.

"Europe will pay for what they have done. God willing, the question of the European Union will again be on the table after April 16," said Erdogan, adding that Turks living in Europe were "oppressed" and "humiliated."

"God willing, our people will bring them (Europe) to account," he said.

Continuing his speech, Erdogan once again threatened after next Sunday's referendum to legally reinstate the death penalty - if it was passed by parliament. Such a move that would automatically end Turkey's bid for accession to the European Union.

Europe is 'collapsing'

Faced with the impending Brexit negotiations and rise in populist and euroskeptic movements Erdogan said Europe is "collapsing."

"They said a century ago that we were the 'sick man'. Now they are the 'sick man'," he said, claiming the European economy weakened every year.

Erdogan clashed with European leaders last month after some of his ministers were prevented from holding pre-election rallies in some European cities. In response to the restriction, Erdogan lashed out at the Netherlands and Germany, comparing their actions to those of Nazis.

ksb/kl (AFP, dpa)