Turkey's flag carrier Turkish Airlines has made it mandatory for all international flight passengers to submit negative PCR virus test results, obtained within the last 72 hours before boarding, the company CEO said Friday.

"On request of our Health Ministry, all passengers coming from abroad as of Dec. 28 will be asked to submit negative PCR virus test results, obtained within the last 72 hours before boarding, as part of Turkey's fight against Covid," Bilal Eksi wrote on Twitter.

Turkey late Sunday temporarily banned flights from the U.K., Denmark, the Netherlands and South Africa due to a new fast-spreading strain of the coronavirus.

The flights between Turkey and the Netherlands resumed Wednesday while the ban is still in place on flights from the others.

Turkish Airlines, in the meantime, conducted several repatriation flights to the U.K. on Friday.