LATEST HEADLINES
• President Vladimir Putin has ordered a "special military operation" in the Donbas region of east Ukraine.
• More than 40 Ukrainian soldiers and around 10 civilians died in the first hours of Russia's military operation, according to an aide to President Volodymyr Zelenskyy.
• Shelling has been reported in the wider Donetsk and Luhansk regions, and in major cities, including Kharkiv and Kyiv.
• An airport in western Ukraine was also targeted, outside Ivano-Frankivsk.
• Video which has been independently verified shows Russian military vehicles crossing the Belarus border in Ukraine.
• Russia's Defense Ministry said its forces had destroyed 74 military targets, "objects of above-ground military infrastructure," on Thursday.
• The State Border Agency says new fighting has begun near the border city of Sumy, close to the border with Russia's Kursk region.
• Footage shared by Ukrainian border guards shows Russian military vehicles crossing the Ukraine border in several places; near Crimea in the south and near Kharkiv in the north. WATCH VIDEO BELOW
• Ukraine said troops have also attacked the south of the country, with missiles striking the port city Odesa as well as landing on the Azov Sea coast, between the Russian border and Crimea. Reuters reported 18 people killed in the attack on Odesa.
• The regional authorities in Kherson, in southern Ukraine near Crimea, said part of the region is "no longer under Ukrainian control."
• The Defense Ministry in Kyiv has claimed Russian troops have been taken prisoner in eastern Ukraine, but without providing more details.
• Ukraine's government has described the developments as a "full-scale invasion."
• NATO put more than 100 warplanes on alert Secretary-General Jens Stoltenberg said.
• Zelenskyy announced that martial law has been imposed across all of Ukraine. "No panic. We're strong. We're ready for anything. We'll defeat everyone because we are Ukraine," he said.
• Putin said his aim is to "demilitarize and 'denazify' Ukraine."
• EU's chief foreign affairs official Josep Borrell said this is "the darkest hours for Europe since World War II" and condemned the Russian action.
• China's Ministry of Foreign Affairs has urged restraint by all parties and issued a safety alert for Chinese people in Ukraine.
A map of the areas in which Russian forces have entered Ukraine according to border guards./AFP
MORE DETAILS
Early on Thursday morning Russia's President Vladimir Putin ordered a military operation to support the Russia-backed breakaway regions in eastern Ukraine, Donetsk and Luhansk.
According to CGTN's correspondent Stephanie Freid, who is in eastern Ukraine, the announcement came very quickly after the administrations in the regions of Luhansk and Donetsk asked for "assistance" from Moscow.
Putin said the mission was to "protect people who have been subjected to bullying and genocide, and for this we will strive for the demilitarization and denazification of Ukraine."
Meanwhile, in Russia some protests have been held against the military action. Several arrests have been made in Moscow's central Pushkin Square.
Moscow has argued that Russians in the eastern regions of Ukraine have been marginalized and became victims of oppression in recent years.
However, Ukraine's Foreign Minister Dmytro Kuleba described the action as a "full-scale invasion of Ukraine."
There have been reports of shelling in major cities around the rest of Ukraine. Some explosions were heard in the capital Kyiv, and artillery and air strikes were reported in Kharkiv, known as Ukraine's 'second city'. Ukraine's military said it has destroyed several aircraft, but Russia has denied these reports. The Mayor of Kharkiv has told residents to remain in their homes.
On Thursday morning CGTN's Stephanie Freid reported that Russian forces are moving towards the Ukrainian capital, Kyiv. It is so far unclear how close Russian troops are to the Ukrainian capital, videos have shown attack helicopters assaulting an airfield near Kyiv.
Ukraine's chief commander has told Reuters news agency that troops are engaged in a battle for the Hostomel airport near the capital city.
Ukraine's Defense Ministry has also said there is an ongoing battle for Chernobyl and Pripyat, an area north of Kyiv. It is the scene of Europe's worst ever nuclear accident in 1986, and officials have expressed concern that nuclear waste could be disturbed.
Ukrainian MP Yegor Chernev told the BBC that President Zelenskyy has approved full military mobilization of Ukrainian forces. The president said Ukraine would arm any citizen who "stepped forward."
Airspace has been closed to commercial flights, and some airports have been targeted by the early strikes in the operation. At least one of these strikes has hit a residential building close to an airport, where casualties have been reported.
Cover image: Ukrainian tanks are seen moving to defend the southern city Mariupol./Carlos Barria/Reuters