Russian forces stepped up mortar and artillery attacks on the recently liberated city of Kherson in southern Ukraine on Wednesday, Ukraine’s military said, while also exerting constant pressure along front lines in eastern regions of the country.

Russia fired 33 missiles from multiple rocket launchers at civilian targets in Kherson in the 24 hours to early Wednesday, the General Staff of Ukraine’s Armed Forces said in its morning report. Russia denies targeting civilians.

Heavy fighting also persisted around the Ukrainian-held city of Bakhmut, now largely in ruins, in the eastern province of Donetsk, and to its north, around the cities of Svatove and Kreminna in Luhansk province, where Ukrainian forces are trying to break Russian defensive lines.

Air raid sirens also sounded across Ukraine on Wednesday morning, officials said. Ukrainian social media reports said the nationwide alert may have been declared after Russian jets stationed in Belarus took off. Reuters was unable to immediately verify that information.

Britain’s defence ministry said in its latest update on the military situation in Ukraine that Russia had likely reinforced the Kreminna section of the frontline as it is logistically important to Moscow and has become relatively vulnerable following recent Ukrainian advances further west.

There is still no prospect of talks to end the war, now in its 11th month.

Ukrainian President Volodymyr Zelensky is vigorously pushing a 10-point peace plan that envisages Russia fully respecting Ukraine’s territorial integrity and pulling out all its troops, something Moscow refuses to contemplate.

Russia’s President Vladimir Putin said on Sunday he was open to negotiations but only on his terms, which include Ukraine accepting the loss of four regions – Luhansk and Donetsk in the east, and Kherson and Zaporizhzhia in the south. Together, they comprise about a fifth of Ukraine’s territory.

Pressure

“There has been very little change in terms of the front line but pressure from the enemy has intensified, both in terms of the numbers of men and the type and quantity of equipment,” said Ukrainian military analyst Oleh Zhdanov.

Zhdanov said that fighting had intensified with Russia deploying armoured vehicles and tanks.

Russian forces abandoned Kherson city last month in one of Ukraine’s most significant gains of the war. Kherson region, located at the mouth of the mighty Dnipro River and serving as gateway to Russian-annexed Crimea, is strategically important.

The joy of Kherson residents over the city’s liberation has quickly given way to fear amid relentless Russian shelling from the east bank of the Dnipro, and many have since fled.

Russian forces shelled the maternity wing of a hospital in Kherson, Kyrylo Tymoshenko, Zelensky’s deputy chief of staff, said on Telegram. No one was hurt and the staff and patients had been moved to a shelter, he added.

Reuters was unable to immediately verify the report.

A Russian strike killed at least 10 people and wounded 58 in Kherson last Saturday, Ukraine said.

In Wednesday’s report, Ukraine’s General Staff also reported further Russian shelling in Zaporizhzhia region and in the Sumy and Kharkiv regions of northeast Ukraine, near to the Russian border.

Reuters was unable to verify the battlefield reports.

In Bakhmut, home to 70,000 people before the war and now a bombed-out ghost town, which Russia has been trying for months to storm at huge cost in lives, Reuters reporters this week saw fires burning in a large residential building. Debris littered the streets and the windows of most buildings were blown out.

“Our building is destroyed. There was a shop in our building, now it’s not there anymore,” said Oleksandr, 85, adding he was the only remaining resident there.

Putin launched his invasion of Ukraine on Feb. 24, calling it a “special military operation” to demilitarize his neighbour, which he said posed a threat to Russia.

Russia set out to subdue Ukraine within days, but its forces were defeated on the outskirts of the capital, Kyiv, in the spring and forced to withdraw from other areas in the autumn.

Putin responded by summoning hundreds of thousands of reservists for the first time since World War Two.

Oil Price Cap

On Tuesday Putin retaliated against a price cap of $60 per barrel of Russian oil imposed on Dec. 5 by Western countries, saying Moscow would now ban oil sales to nations that implement it.

The cap, unseen even in the times of the Cold War between the West and the Soviet Union, is aimed at crippling Russia’s military efforts in Ukraine – without upsetting markets by actually blocking its supply of oil.

The oil ban decree from Putin was presented as a direct response to “actions that are unfriendly and contradictory to international law by the United States and foreign states and international organisations joining them”.

Russia is the world’s second largest oil exporter after Saudi Arabia, and any actual disruption to its sales would have far-reaching consequences for global energy supplies.

In a late night address on Tuesday, Zelensky said 2023 would be a decisive year. “We understand the risks of winter. We understand what needs to be done in the spring.”