Report: 626 Schools, Establishments to Close After Failed Coup in Turkey |

Turkey's state-run news agency says authorities are closing 626 private schools and other establishments following a failed coup attempt, blamed on followers of a U.S.-based Muslim cleric.

Anadolu Agency says the decision was made Wednesday by the Education Ministry and that the schools were under investigation for "crimes against the constitutional order and the running of that order" - without saying the schools are linked to a movement led by the cleric, Fethullah Gulen.

Earlier, media reports said the government, expanding its purge of suspected coup backers, has begun to revoke the licenses of 21,000 teachers at private schools.

Gulen has denied being behind the failed coup.

Meanwhile, Standard & Poor's has downgraded its credit rating for Turkey deeper into "junk" status, citing the failed coup and political turmoil.

The rating agency lowered its main sovereign rating for Turkey to BB/B from BB+/B, both of which are considered junk.

S&P said it expects a period of heightened unpredictability in the country and maintains a negative outlook, which indicates that further downgrades are possible.

It said in a statement issued Wednesday: "The negative outlook reflects our view that Turkey's economic, fiscal, and debt metrics could deteriorate beyond what we expect, if political uncertainty contributed to further weakening in the investment environment."