Thick fog has enabled Russian troops to move further into the key strategic city of Pokrovsk in eastern Ukraine.
Ukraine's 7th Airborne Assault Corps says weather conditions, particularly dense fog, have prompted Moscow to intensify its bid to get increasing numbers into the ruined city and encircle Ukrainian forces.
Russian forces have spent more than a year trying to seize the city. Ukraine's military says there may now be 300-500 Russians there and President Volodymyr Zelensky says the situation remains difficult.
Meanwhile, army chief Oleksandr Syrskyi says the situation on the front line in the southeastern Zaporizhzhia region has 'significantly worsened', with the loss of three settlements.
Syrskyi stated that Russia was most active around Pokrovsk. A video has gone viral on social media showing Russian soldiers openly driving through a hazy road on civilian cars and motorbikes.
The BBC has verified the location where the video was filmed as the southern outskirts of the town on the Selidove-Pokrovsk highway.
For several days, fog obscured visibility for aerial reconnaissance, says a drone pilot with the call-sign 'Goose'. He explained that under such conditions, Russians had no fear of launching assaults using a column of vehicles, which typically would have been targeted by Ukrainian drones.
The Ukrainian drone pilot reported that despite regular detection and elimination of small Russian groups attempting to advance, the increasing numbers and strategic use of weather conditions have raised concerns.
Recent developments indicate that the situation in Pokrovsk is precarious, with most parts of the city now falling within a 'grey zone' of contested control. As Moscow teams up with Russian troops to encircle Pokrovsk and neighboring areas, Ukrainian defenses are becoming increasingly strained under sustained attacks.
