As Ukraine’s second-largest city, Kharkiv, came under a barrage of Russian air attacks and rockets on Tuesday morning, 29-year-old Taras Kovalchuk ventured outside to take his dog Yoko for a short walk.

Shortly after leaving his flat in central Freedom Square, his phone started buzzing, as a flurry of alerts from local authorities warned him of impending air raids.

A friend sent a message asking if he was okay, and a push notification informed him that a missile had hit the square.

“Until the missile destroyed my apartment, I firmly believed that I would stay in Kharkiv,” he told Al Jazeera.

Kovalchuk returned to his apartment, opposite the regional administration building which was hit by a Russian military attack shortly after sunrise, to a scene of devastation.

CCTV footage showed a fireball engulfing the street in front of the Soviet-era building. An emergency official said the bodies of at least six people had been pulled from the ruins and at least 20 others had been injured.

It was not immediately known what type of weapon was used or how many people were killed. Ukrainian officials said at least 11 people were killed. President Volodymyr Zelenskyy said there were dozens of victims and accused Russia of war crimes.

“What I saw was the craziest thing of my life,” Kovalchuk said. “I couldn’t imagine that a human being could behave like that with another human being.”

Central Café, the local cafe where he had spent many mornings over the years, had been destroyed by the blast. Upstairs, the windows of his apartment had shattered and the doors had flown off their hinges. Glass and debris lined the floor, and furniture was knocked over.

Kovalchuk grabbed the bug out bag he had packed for an emergency when Russia launched its invasion of Ukraine on Thursday and set off on a 40-minute walk to the train station, navigating a ravaged city whom he barely recognized amid the constant noise of the bombardments. .

Tuesday marked the first time the Russian military struck the center of Ukraine’s second-largest city, whose population of 1.4 million is overwhelmingly Russian-speaking. Residential neighborhoods have been shelled for several days.

Some 87 apartment buildings in Kharkiv have been damaged and several neighborhoods in Kharkiv have no water, electricity or heating, Mayor Ihor Terekhov told Ukrainian TV channels.

Anton Gerashchenko, adviser to the Ukrainian interior minister, said that “practically there are no longer any areas in Kharkiv where an artillery shell has not yet hit”.

The Russian military denied attacking civilian targets, despite reports that it was bombing residential buildings, schools and hospitals. He says he only targets Ukraine’s military infrastructure, air defense and air force with high-precision weapons.

Kharkiv put up fierce resistance to Moscow’s advance, with Ukrainian forces capturing a unit of Russian troops that entered the city over the weekend.

Beginning Monday, Russian forces unleashed a barrage of multiple-launch rocket fire against residential neighborhoods, killing at least 10 civilians, including three children, and wounding at least 40, according to local officials.

Terekhov, the mayor of Kharkiv, said one in four people in the city had relatives who lived across the border. “But the city’s attitude towards Russia today is completely different from what it was before,” he said in a video statement online.

“We did not expect this to happen: total destruction, annihilation, genocide against the Ukrainian people – this is unforgivable.”

On Wednesday, clashes erupted after Russian paratroopers landed in Kharkiv, the Ukrainian army said.

Kovalchuk fled the city and found refuge with a friend. Just last week, he was writing for a digital magazine and blogging about travel. Now he can barely contain the anger that the invasion of his home country and the destruction of his city has stirred in him.

“We can’t call [Russians] humans – humans don’t act like them with civilians,” he said. “The world must stop Russia now.”