It's back and forth' Ukraine's army resists Russia's latest push for land

From a line of trees the Ukrainian gun team prepares to fire. An artilleryman, Yurii, loads a 152mm shell into an old Soviet-made howitzer. "We are ready!" Yurii says. "Fire!" the unit's commander replies. There is an almighty boom before white smoke fills the dugout, which is hidden beneath camouflage nets and cut pine branches. From the undergrowth, a chiffchaff resumes its warbling.

- Luke Harding

Nearby, in the north-east of Ukraine, Russian troops were trying to advance. In February 2022, they rolled into the town of Dvorichna at the beginning of Vladimir Putin's full-scale invasion. Six months later, Ukraine's armed forces pushed them out as part of a successful counteroffensive in the Kharkiv region. In January, the Russians came back and occupied Dvorichna for a second time.

The battle is taking place on either side of the picturesque Oskil River. Before the war, it was a place for recreation. Visitors would grill kebabs on its sandy beaches or go kayaking past a ridge of low chalk hills and a small national park. Now it is a zone of war, waged by drones, artillery and bombs. The Russians are trying to expand a slender bridgehead on the river's right bank. Their goal is to seize the R79 highway leading to the railway hub of Kupiansk, immediately to the south and, after that, to encircle Kharkiv, Ukraine's second city.

"Our task is to stop them from crossing the river. We do this by firing at their logistics in the rear," explained Serhii, an artillery captain with the 1st or Burevii brigade of Ukraine's national guard.

In the past two months, the Russians had scaled back their attempt to bring reinforcements across the Oskil, Serhii said, because of heavy losses. As soon as Russian engineering teams build pontoon bridges, his battery destroys them, he added. Video shows how three Russian armoured personnel carriers were hit. They sank. Others got stuck on the bank and were finished off by kamikaze drones. The corpses of Russian soldiers lay around. "Sometimes they collect their dead. Sometimes not. Dogs eat their remains," Yurii - the artilleryman - said matter-of-factly.