Turkish officials say that nearly 8,000 police officers have been suspended, reportedly on suspicion of having links to the coup attempt at the weekend.
Some 6,000 members of the judiciary and military, including generals, have been detained.
President Recep Tayyip Erdogan vowed to purge state bodies of the “virus” that caused the revolt.
The US Secretary of State, John Kerry, has stressed the importance of democratic rule.
Speaking in Brussels where he has been meeting European foreign ministers, Mr Kerry said the United States stood squarely on the side of the elected leadership in Turkey.
“We will certainly support bringing perpetrators of the coup to justice – but we also caution against a reach that goes well beyond that.”
The Turkish government claims cleric Fethullah Gulen was behind the plot.
Mr Gulen lives in the US and strongly denies any involvement.
State media reported on Monday that more than 100 generals and admirals had been detained in raids across the country.
Eight Turkish military officers who fled to Greece by helicopter appeared in court in the Greek border city of Alexandropouli charged with entering the country illegally. Proceedings were adjourned until Thursday.
Turkey has requested their extradition; they have applied for asylum in Greece.
President Erdogan told a crowd on Sunday that Turkey would consider reinstating the death penalty.
Capital punishment was abolished in 2004 as part of Turkey’s bid to join the European Union. Nobody has been executed in the country since 1984.