Protests and Parties: Turkish President Claims Referendum Victory

A woman supporting Turkish President Recep Tayyip Erdogan waves a Turkish national flag as she celebrates during a rally near the headquarters of the conservative Justice and Development Party (AKP) on April 16, 2017, in Istanbul.

Erdogan hailed Turkey for making a "historic decision" as he claimed victory in the national referendum on a new constitution expanding his powers. The "Yes" campaign to give the president expanded powers won in a tightly-contested referendum although the "No" camp had closed the gap, according to initial results. But Turkey's two main opposition parties said they would challenge the results.

Supporters of Turkey's president wave flags and brandish smoke bombs during a rally after the initial results of a nationwide referendum.

A man holds a child as they wait for President Erdogan to appear for a speech at the AKP headquarters in Istanbul, on April 16.

Supporters of the president celebrate the victory of the ''Yes'' campaign near Taksim Square, in Istanbul. The constitutional referendum will give President Erdogan more power by introducing a presidential system.

Opponents of the referendum chant slogans as they protest in Istanbul into the early Monday morning hours, April 17. Hundreds of demonstrators marched in a central neighborhood, clanking pots and pans and chanting "this is just the beginning, the struggle will continue."

Protesters take to the streets in Istanbul as the first results of the referendum emerge, April 16.

People celebrate late into the night in Istanbul, April 16.

A woman flashes a four finger sign called "the rabia sign" as she celebrates and waits to greet the Turkish president when he arrives for his speech in Istanbul, April 16.

Erdogan's supporters celebrate in Istanbul.

Protesters take to the streets in Istanbul.

Riot police officers detain a protester outside the Supreme Electoral Board in Ankara, late Sunday night, April 16.

A man reads Posta newspaper bearing a headline which translates as "Yes to New System" in Istanbul on April 17.

The president is greeted by his supporters as he leaves Esenboga Airport in a bus in Ankara, April 17.

President Erdogan greets people, accompanied by Turkish parliamentary speaker Ismail Kahraman after praying at Eyup Sultan mosque in Istanbul, April 17.

Supporters of the president await his arrival to Ankara on April 17.

The president's supporters wave national flags as they await his arrival at the Presidential Palace on April 17.

Supporters celebrate while waiting for President Erdogan to arrive at the presidential palace.