KYIV, Ukraine

Ukraine on Sunday entered the fourth day since the start of large-scale Russian military intervention against the country. 

At least one child, a 6-year-old boy, was killed in an attack on the children’s specialized hospital late Saturday in Ukraine's capital Kyiv.

Ohmatdet, one of the largest children’s multidisciplinary hospitals in Ukraine, was targeted during the Russian military intervention, leaving another five people, including children, wounded, according to Anton Gerashchenko, an adviser at Ukraine's Internal Affairs Ministry.

"Five people were brought (to the hospital). Unfortunately, one child died before being transported to the hospital. One received complex injuries to the limbs and head, now in the operating room. One child received minor finger injuries. And two adults are with moderate injuries. Now they are all being helped," local news outlet TSN reported, quoting Sergii Chernyshuk, a medical director of the hospital.

"The children of Ukraine need peace. Desperately. Now," the UN said on Twitter.

Last Thursday, UNICEF in a statement said it is "deeply concerned" that intensifying hostilities in Ukraine pose an "immediate threat" to the lives and wellbeing of the country’s 7.5 million children.  

Air raid siren sounds

Also, sounds of bombardment and shelling early Sunday in Kyiv were accompanied by gunfire near the iconic Independence Square of the capital.

Near-constant air raid siren sounds were heard again at 8.10 a.m. local time (0610GMT).

Thousands of people who have not left the city across Kyiv spent the night taking shelter in subway stations, building basements, or underground car parks.

Confirming that "tens of thousands of weapons" were distributed in Kyiv to the volunteers of the Territorial Defense structure, Gerashchenko said the "enemy sabotage groups" are operating in the city, adding that there were also the cases of "friendly fire."

Authorities said the Russian "sabotage and reconnaissance groups" are being sought in Kyiv, which is currently under curfew until Monday morning.

Early Sunday, Mykola Povoroznyk, the first deputy head of Kyiv's State Administration, said the capital remains under the control of the Ukrainian army and Territorial Defense Forces.

"The situation in Kyiv is calm. The capital is completely controlled by the Ukrainian army and territorial defense. There were several clashes with groups of saboteurs at night," said Povoroznyk. 

Unexpected resistance

After facing stronger-than-expected resistance from the Ukrainian side, Russian authorities said they will intensify the attacks on the neighboring country.

So, the Russian Defense Ministry on Saturday ordered troops to attack Ukraine in all directions "in response to Kyiv's refusal to negotiate."

Meanwhile, Ukraine's Defense Minister Oleksii Reznikov on Sunday hailed his country's resistance against Russia's attacks.

Reznikov said on Twitter: "72 hours of resistance! The world didn’t believe. The world doubted. But we did not just stand, we confidently continue to fight with Russian occupant! We showed the world - don’t be afraid Russia, be strong & repel it! Support of Ukraine must be more stronger! Your safety depends on us!"

On Sunday, the National Bank of Ukraine opened a special fundraising account to support the country's armed forces.

Amid Russian attacks, Ukraine this week imposed martial law and general mobilization across the country.  

Oil depot attack

Early Sunday, authorities in the Vasylkiv city of the Kyiv region announced that Russian forces had fired a missile at an oil depot.

Vasylkiv Mayor Nataliia Balasynovych confirmed that an oil depot in the village of Kriachky near Vasylkiv was on fire.

On his turn, Gerashchenko on Telegram said Russian forces launched "another cruise or ballistic missile strike" against Vasylkiv.

He noted that the missile strikes have caused a fire in the area.

Oleg Nikolenko, a spokesperson for Ukraine's Foreign Ministry, on Twitter said the Ukrainian army downed a rocket allegedly fired from Belarus towards Kyiv.

"Minutes ago, Ukrainian Air Force shot down a cruise missile launched at the capital of Ukraine, Kyiv, by a TU-22 bomber from the territory of Belarus. This is another war crime committed against Ukraine and its people," he said.

Meanwhile, in the Bucha city of the Kyiv region, a shell hit a nine-floor residential building early Sunday. No casualties or injuries were reported according to initial reports.

According to the Ukrainian figures, the country's armed forces have shot down 16 planes, 18 helicopters, hundreds of Russia's military vehicles, with around 4,300 Russian soldiers killed and 200 taken hostage.