On Wednesday, Turkish Airlines announced via its website that it has cancelled all flights to Yemen's Aden and Sanaa cities until June 1 due to political unrest in the country.Previously, on March 3, the airlines announced that it had cancelled a total of 20 flights from Istanbul to Aden and Sanaa international airports for about a week after Saudi-led coalition airstrikes hit al-Daylami air base, located close to Yemeni capital, Sanaa