Satellite imagery reveals an increase in defensive construction at airfields including Khalino in the Kursk region and the Saki airbase in annexed Crimea.
The injuries were reported one day after officials said Russian attacks had killed at least seven civilians and injured dozens more in Ukraine’s Sumy, Kharkiv, Donetsk and other regions Tuesday.
Among the victims were two women who were killed when a drone struck a van carrying five farm workers near the village of Shchegolek, authorities said.