Turkey's finance ministry has suspended about 1,500 employees over suspected links to Fethullah Gulen, the US-based Muslim cleric who Ankara accuses of being behind the failed coup, according to a ministry official.
The official said the suspensions were in all departments and across the country.
Earlier on Monday Turkey repeated its call for the US, its NATO ally, to extradite Gulen, who lives in self-imposed exile in Pennsylvania.
Gulen denies claims his network was behind the coup attempt.
Angela Merkel has warned Turkey's president that the reintroduction of the death would be incompatible with Turkey's goal of EU membership.
The German chancellor told Recep Tayyip Erdogan reintroducing the death penalty was "in no way compatible" with his country's plans to join the EU, a spokeswoman for the chancellor said.
The comments come as Mr Erdogan contemplates capital punishment for those behind the failed coup attempt in Turkey.
Turkey abolished capital punishment in 2004, allowing it to open EU accession talks the following year, but the negotiations have made little progress since then.
America's ambassador to Turkey has said it will consider any extradition request if it meets US legal requirements.
But US ambassador John Bass said his country was willing to help Turkey investigate the coup attempt, rejecting any suggestion America was trying to undermine Turkish security.
He said it was "categorically untrue" that the US had backed the coup attempt.
A man has been killed in an apparent shootout between Turkish police and military units in Ankara.
The circumstances of the shooting were not immediately made clear.
Prime Minister Binali Yildirim hinted that a refusal to transfer the 75-year-old bitter rival of President Erdogan will bring trouble to the two countries' relationship.
We would be disappointed if our (American) friends told us to present proof even though members of the assassin organisation are trying to destroy an elected government under the directions of that person.
Gulen has strongly denied any involvement in Friday's coup attempt and US Secretary of State John Kerry has said that Ankara must provide genuine evidence that withstands scrutiny when it requests his extradition.
Yildirim said that Turkey has documents detailing the responsible parties of the failed coup attempt.
The coup plotters had detailed plans on who would take ministerial posts and who would act as the head of martial law, he said.
Demonstrations are expected to take place outside the US consulate building in Turkey today, with American citizens urged to avoid the area.
The US Consulate General in Istanbul issued the warning as tensions between the two countries grew over Turkey's demands for the extradition of US-based cleric Fethullah Gulen in relation to Friday's attempted coup.
Turks have been marching and protesting in public places to demonstrate support for President Tayyip Erdogan since early on Saturday morning.
On Twitter, some accounts urged followers to meet at the US Consulate on Monday afternoon.
The prime minister of Turkey has said that is "not correct" to make a hasty decision about bringing back the death penalty following an attempted coup on Friday.
Speaking after a cabinet meeting, Binali Yildirim said the country cannot "ignore the demands of our people" but said that reinstating capital punishment would require constitutional change.
EU High Representative for Foreign Affairs Federica Mogherini said that no country that has the death penalty can become and EU member.
She said that Turkey is part of the Council of Europe and is therefore bound by the European Convention on Human Rights.
Secretary of State John Kerry has warned Turkey not to go "too far" in bringing order following Friday's attempted coup.
Speaking at a news conference in Brussels, Kerry said the US supports bringing the perpetrators to justice but says that President Erdogan is "firmly urged" to maintain calm, uphold the rule of law and show respect for institutions.
The US has a formal process for dealing with extradition requests, Turkey must send evidence not allegations.
Erdogan has accused Gulen, a 75-year-old cleric, of organising the attempted coup that has so far has left more than 200 people dead.
Gulen staunchly denies any involvement in the plot.
Turkey has removed 8,000 police officers from their roles due to alleged links with Friday's failed coup attempt, a senior security official has told Reuters.
Turkey's president broke down in tears at a funeral for one of his supporters as he vowed to cleanse his country.Read the full story ›