Hundreds of demonstrators have taken to the streets of Istanbul to protest against the outcome of last week’s controversial referendum in which President Recep Tayyip Erdogan’s executive powers were expanded.

The protesters chanted anti-Erdogan slogans during Saturday’s march, vowing to stay on the streets until the referendum’s result is annulled.

Their banners read, “No to one-man rule,” “Referendum should be annulled,” and "No. We won!”

A protester held up a cardoon of the Turkish president, reading, “They don’t let me be the president.”

“There is hatred and anxiety around us. We are going in the direction opposite to one we should be going. I am trying to make myself heard as this is the only thing I can do,” said protester Aysu Kaya.

Erdogan’s “Yes” campaign won 51.36 percent of the votes in the April 16 referendum, while the “No” campaign gained 48.64 percent.

Turkey’s three largest cities including Istanbul, Ankara and Izmir voted against Erdogan’s expansion of power.

Erdogan declared victory in the vote, however, his opponents said the referendum was deeply flawed.

The constitutional reforms could secure Erdogan’s presidency for another two terms until 2029.