Ukrainian forces advanced between 200 meters and 1.1 kilometers in various areas around the key battleground city of Bakhmut and are now on the offensive, according to military reports.

“In the direction of Bakhmut, our troops switched from defense to offensive,” Ukraine’s Deputy Defense Minister Hanna Maliar said in a post on Telegram. “Over the past day, we have advanced from 200 to 1,100 meters in various sections of the Bakhmut direction.”

The news comes as multiple media outlets reported Thursday that Ukraine’s long-awaited counteroffensive had begun, with Kyiv’s forces battling to retake territory occupied by Russia.

In its daily Ukraine intelligence update on Thursday, the U.K.’s Ministry of Defense said: “Amidst a highly complex operational picture, heavy fighting continues along multiple sectors of the front.”

It added: “In most areas Ukraine holds the initiative.”

Meanwhile, Russian Defense Minister Sergei Shoigu said in a video released Thursday that Ukrainian forces had mounted an attack in the area of Zaporizhzhia, with 1,500 troops and 150 armored vehicles. Shoigu claimed that Russian forces had held off the Ukrainians.

Ukrainian officials have previously said they would not announce the beginning of the counteroffensive, so as not to ruin the element of surprise.

In his nightly address Wednesday, Ukrainian President Volodymyr Zelenskyy said cryptically: “I thank each of our warriors, all units, all brigades that continue to fight the occupiers. The Bakhmut direction, Avdiivka, all of Khortytsia, all of Tavria — great job!”