Russian forces moved into Kyiv, capital of Ukraine, on the second day of its military operation in the country.
BBC reports that Ukrainian authorities have confirmed Russian troops are in the northern district of Kyiv.
Ukrainian President, Volodymyr Zelensky, said at least 137 Ukrainians had been killed and 316 soldiers wounded since the Russian invasion began.
Russian armoured vehicles reportedly advanced into the capital city though the northern district.
Thousands of people in Kyiv are currently taking shelter in metro stations to avoid being caught up in crossfire by Russian forces heading for the city.
The Russian troops broke into Ukraine in the early hours of Thursday.
Udovichenko, an accountant, told Aljazeera that he had taken his 82-year-old mother Olha Krisevich underground with him.
The pair were joined by dozens of other people, who arrived shortly after 7pm local time (17:00 GMT) on Thursday carrying blankets, suitcases and even, in some instances, pets.
Zelensky in a video message posted on his Facebook page also said other states were “afraid” to support Ukraine’s accession to NATO.
The country’s Interior Ministry of Defense also announced on Thursday that all Ukrainian men ages 18 through 60 will be barred from leaving the country.
“The State Border Guard Service of Ukraine reports that due to the imposition of martial law in Ukraine, the departure of a certain category of citizens from Ukraine is temporarily restricted. In particular, male citizens of Ukraine aged 18 to 60 are prohibited from leaving Ukraine.
“Such a rule will apply for the period of martial law. We ask citizens to take this information into account.”
This follows the Ukrainian government’s decision to give firearms to any citizens who wants to fight Russian troops.
About 100,000 people fled as explosions and gunfire rocked major cities.
Zelenskiy said he understood Russian troops were coming for him but vowed to stay in Kyiv.
“(The) enemy has marked me down as the number one target,” Zelenskiy said in a video message. “My family is the number two target. They want to destroy Ukraine politically by destroying the head of state.”