Turkey widened a crackdown on suspected supporters of a failed military coup on Sunday, taking the number of people rounded up in the armed forces and judiciary to 6,000, and the government said it was in control of the country and economy.
Erdogan's supporters of gathered in front of his Istanbul home to call for the plotters to face the death penalty, which Turkey outlawed in 2004 as part of its efforts to join the European Union (EU).
"We cannot ignore this demand," Erdogan told the chanting crowd. "In democracies, whatever the people say has to happen."
He said a "terror group" led by Gulen had "ruined" the armed forces, that its members were being arrested in all military ranks, and that a purge of this "virus" would continue.
The president has called on Turks to stay on the streets until Friday, and late into Sunday night, his supporters thronged squares and streets, honking horns and waving flags.
Pictures on social media showed detained soldiers stripped to the waist, some wearing only their underpants, handcuffed and lying packed together on the floor of a sports hall where they were being held in Ankara.
One video posted on Twitter showed detained generals with bruises and bandages. Akin Ozturk, head of the air force until 2015 and identified by three senior officials as one of the suspected masterminds of the coup plot, was among those held.
The Foreign Ministry raised the death toll to more than 290, including over 100 rebels, and said 1,400 people were hurt.
Europe uneasy on Erdogan's crackdown
The violence shocked the nation of almost 80 million, once seen as a model Muslim democracy, where living standards have risen steadily for more than a decade and where the army last used force to stage a successful coup more than 30 years ago.
It also shattered fragile confidence among Turkey's allies about security in the NATO country, which is a leading member of the U.S.-led coalition against Islamic State. Turkey had already been hit by repeated suicide bombings over the past year and is struggling to contain an insurgency by Kurdish separatists.
France's foreign minister said on Sunday that questions needed to be asked on whether Turkey was a viable partner in the fight against Islamic State in Syria.
"There are questions that are being asked and we will ask them. It [Turkey] is partly viable, but there are suspicions as well. Let's be honest about this," Jean-Marc Ayrault told France 3 television.
He said he would raise the issue at meeting of the anti-Islamic state coalition in Washington next week. A French official later sought to clarify Ayrault's comments, saying he had not meant to put in question Turkey's viability in the fight against Islamic State, and that Ankara remained a crucial partner for the coalition to that end.
With expectations growing of a heavy clampdown on dissent, European politicians warned Erdogan the coup attempt did not give him a blank check to disregard the rule of law, and that he risked isolating himself internationally as he strengthens his position at home.
Broadcaster NTV cited Justice Minister Bekir Bozdag as saying more arrests were expected.
By Sunday evening,