Civilians in Ukraine's eastern strategic logistics hub of Pokrovsk have just a week or two to evacuate as Russian troops press toward the city, an official said on Monday.

The head of city military administration, Serhiy Dobriak, on Monday stressed again that civilians should leave as fast as possible.

Civilians have "a week or two, no more," Dobriak told Radio Liberty's Ukrainian Service when asked about time left for evacuations considering the pace of Russian forces' advance. Authorities have the capacity to evacuate at least 1,000 people a day, he added, but only 500-600 people per day are currently leaving.

Some 53,000 people, including almost 4,000 children, remain in Pokrovsk and adjacent settlements, the regional governor of Donetsk Oblast, Vadym Filashkin, said on Telegram.

The forced evacuation of families with children was starting in the Pokrovsk area, he added.

Meanwhile, curfews in settlements lying close to Pokrovsk — Myrnohrad, Selydove and Novohrodivka — have been tightened.

"The situation at the front is very difficult and it is likely that the curfew will be tightened in other localities as well," Filashkin said on national television.

Russia claims town in eastern Ukraine

The Pokrovsk front remains the area with the most intense fighting in eastern Ukraine, with a record number of clashes reported last week as the Ukrainian military proceeds with its shock incursion into Russia's Kursk region.

On Monday, Ukraine's General Staff reported 145 combat clashes for the last 24 hours, with 45 alone in the Pokrovsk direction.

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Another 24 clashes took place near the mining town of Toretsk, some 47 kilometres from Pokrovsk, which has seen an intensified Russian push as well.

"Heavy fighting continues in the Pokrovsk direction. The defence forces are also doing everything necessary to protect Toretsk," army chief Oleksandr Syrskyi said on Telegram.

Russia's Defence Ministry said on Monday that its forces had captured the town of Zalizne in Donetsk. Zalizne, which Russia calls by its Soviet-era name of Artyomovo, adjoins Toretsk.

3rd Russian bridge damaged

Meanwhile, Ukraine says it has seized more than 80 Russian settlements in an area of more than 1,150 square kilometres in Kursk since launching a surprise strike on Aug. 6, the biggest invasion of Russia since the Second World War.

President Volodymyr Zelenskyy says the assault on the Kursk region bordering eastern Ukraine is aimed at carving out a buffer zone and wearing down Moscow's war machine, more than two years since Russia's full-scale invasion.

"We are achieving our goals," he wrote on the Telegram messaging app on Monday.

Kyiv's air force chief said on Sunday that his forces had destroyed two bridges in recent days to weaken enemy logistics.

Russia confirmed on Monday that Ukraine had struck and damaged a third bridge over the Seym River. Ukraine has not yet commented on the third reported strike.

More than 121,000 people have been evacuated from nine border districts in Russia's Kursk region, the emergencies ministry said on Monday.