Turkish President Recep Tayyip Erdogan on Monday announced a nationwide "full closure" from Thursday until May 17 to curb a surge in coronavirus cases and deaths.
It will include a continuous lockdown, school closures and intercity travel restrictions.
Total daily cases of the virus peaked above 63,000 on April 16 before dropping sharply to below 39,000 on Sunday, while the daily death toll has remained above 300 for the past week.
All intercity travel will need approval from authorities and all schools will close classrooms, Mr Erdogan said after a Cabinet meeting.
He said manufacturing and food businesses would be exempt from the new restrictions.
Daily case numbers must fall below 5,000 by the end of Ramadan, or about May 12, Mr Erdogan said.
Doctors in Turkey have been urging a lockdown during Ramadan, expecting cases to continue rising as families get together during the holy month.
This month Mr Erdogan brought in a weekend lockdown that limited restaurants to take away and delivery only, and imposed a curfew from 9pm to 5pm.
How to use a rapid Covid-19 lateral flow test
In March, he lifted pandemic restrictions in the hope of boosting the fragile Turkish economy.
Turkey's current wave of coronavirus is the worst it has seen since the start of the pandemic, and doctors say 75 per cent of cases are of the more virulent strain identified in Britain.
Coronavirus around the world: in pictures
