Residents of the southern Bulgarian town of Galabovo were asked to stay inside their homes and close their windows for an afternoon due to excessive sulphur dioxide levels in the air. At its peak, the pollution reached 655.4 micrograms per cubic metre – nearly double the maximum permitted level, which is 350 micrograms per cubic metre. The local environmental authority has repeatedly issued orders to the three nearby thermal power plants from the Maritsa-Iztok Complex to reduce their output in the interests of cleaner air.