Authorities have been unable thus far to identify the origin of a bluish haze spotted over southern and central Estonia on Thursday, BNS reports.
The Rescue Board (Päästeamet) says it has received a number of calls from concerned residents in the region, starting at around noon on Thursday, but as yet has not identified the origins of the haze, which reportedly smells of smoke.
A spell of warm and dry weather at the beginning of April brought the first fire warnings of the year from the Rescue Board, but any obvious fire source which might have caused Thursday's phenomenon, including over the border in the Pskov Oblast of Russia, has not been detected either by the Rescue Board or its counterpart in Pskov, BNS says.
A Police and Border Guard (PPA) plane is due to make an observation flight over the affected region in an effort to get to the bottom of the matter, a Recue Board spokesperson said.
Some social media reports have been claiming that the haze is caused by dust particles, originating in the Sahara Desert, in the atmosphere.
Editor: Andrew Whyte