Ukrainian servicemen fired M119 howitzer towards Russian positions next to the eastern city of Bakhmut on Friday.
An aide to Ukrainian President Volodymyr Zelenskyy announced that Ukraine has decided to fight in Bakhmut. The reason for the decision was interpreted as squeezing the best troops of the Russians and slowing them down before the spring attack.
The comments, by Mykhailo Podolyak, were the latest signal of a shift by Kyiv this week to continue the defense of the small eastern city, site of the war's bloodiest battle as Moscow tries to secure its first victory in more than half a year.
Russia had made Bakhmut a prime target. Hundreds of reservists and mercenaries were recruited for the city.
Troops were able to capture the eastern part of the city, as well as the suburbs to the north and south. But they failed to close the circle around the Ukrainian defenders.
The Kyiv government was planning to accept the defeat at Bakhmut and withdraw to positions west of the city. But earlier this week, a new decision was made to continue fighting in Bakhmut.
In a morning update, the Ukrainian general staff reported a large number of attacks along the front and said "the enemy is not halting its attacks on Bakhmut."
Moscow says capturing Bakhmut would be a step towards capturing all of Ukraine's Donbas industrial region, a major objective. Russian Defence Minister Sergei Shoigu said on Tuesday seizing the city would punch a hole in Ukrainian defenses and let Moscow advance deeper.
The intense trench warfare, described by both sides as a meat grinder, has led to huge losses. But Kyiv's decision to stay and fight rather than withdraw was a sign it believes Russia's losses are far worse than its own.