Turkish President Recep Tayyip Erdogan canceled his appearances for a second day on Thursday after falling ill with a stomach bug.

On Thursday, he had been scheduled to appear at a rally in Mersin as well as to inaugurate Turkey's first nuclear power station — a facility on Turkey's southern coast that is built, owned and operated by Russia's state nuclear energy company Rosatom. 

Instead, Erdogan addressed the nuclear plant opening via video link, along with Russian President Vladimir Putin.

Erdogan boasted that he was "proud to be making the move that will place Turkey among the nuclear power countries of the world."

Putin described the plant as the "biggest project in the history of Turkish-Russian ties."

Erdogan falls ill mid-interview

Erdogan fell ill during a live TV interview on Tuesday while campaigning for the election next month.

The interview was briefly cut and a concerned voice could be heard in the background. Erdogan returned around 20 minutes later to finish the interview.

The Turkish president said on Wednesday that he would take some time off to "rest at home under the advice of our doctors."

What Turkish officials say about Erdogan's health

Late on Wednesday, Erdogan's communications director Fahrettin Altun shared screenshots of speculation that the president had suffered a heart attack and was in hospital.

"We categorically reject such baseless claims regarding the president about his health," Altun said.

Meanwhile, Vice President Fuat Oktay said Erdogan was doing well.

"We are in constant contact," he said. "He has caught a little cold."

The election campaign in Turkey

Erdogan has been campaigning frequently as part of his bid to continue a two-decade election-winning streak.

However, his popularity has fallen due to economic issues and the impact of February's earthquakes that claimed more than 50,000 lives.

He is now neck-and-neck in the polls with opposition candidate Kemal Kilicdaroglu, who is backed by a coalition of secular, conservative and nationalist factions.

On Thursday, polls opened for Turks in Germany — the largest Turkish diaspora community numbering 1.5 million eligible voters — to cast their vote from overseas. The first round of the election in Turkey will be held on May 14.

zc/msh (AFP, AP, Reuters, dpa)