For the very latest on Russia's invasion of Ukraine, see our live page.
Fierce battles are raging close to Kyiv, as Russian forces continue their advance through Ukraine. Troops are fighting for control of an airfield on the outskirts of the capital, which could act as a springboard into the city for the Russian army. Ukraine's president says Kyiv was hit by multiple missiles strikes before dawn, with reports suggesting one hit an apartment building, injuring three people. In a video address, Volodymyr Zelensky appealed for a ceasefire and talks to end hostilities. "The sooner the conversation begins, the smaller Russia's losses will be," he added.
Russian forces continue to advance from the north, south and east. Ukraine says 137 citizens - soldiers and civilians - were killed on Thursday. Russian soldiers have gained control of the Chernobyl former nuclear site, about 130km (80 miles) north of Kyiv. And UN estimates suggest more than 100,000 people have already fled their homes. Our correspondent Orla Guerin captures the mood of disbelief and uncertainty in the frontline eastern city of Kostyantynivka. As one man tells her: "I can't even understand what we should do. We're civilians, not military people." Most people have stayed, sheltering in bunkers or underground metro stations, while a general mobilisation orders all who can carry arms to defend their country.
In his address, Mr Zelensky urged Western allies to help. "This morning we are defending our state alone. Like yesterday, the world's most powerful forces are watching from afar," he said. Western nations have stepped up sanctions against Russia, pledging aid and military supplies to Ukraine, with the US ordering 7,000 additional troops to Europe to "reassure Nato allies". French President Emmanuel Macron says he asked Russian President Vladimir Putin to end the attack in a "frank, direct, quick" call. But Mr Putin defends the invasion as the only way to secure Russia's borders and protect people in parts of Ukraine's east, where state forces have been battling Moscow-backed separatists since 2014. There have, however, been anti-war protests in Russia - met by some arrests - with many ordinary Muscovites shocked at the conflict.

The UK has joined the US and Europe in imposing sanctions on Moscow, excluding major Russian banks from the financial system, freezing the assets of 100 new individuals and businesses and banning exports of high-tech items and oil refinery equipment to Russia. Prime Minister Boris Johnson says they are "the largest and most severe package of economic sanctions that Russia has ever seen". However, our political editor Laura Kuenssberg says there's a "grisly acceptance the UK's chosen approach to confronting Vladimir Putin will not immediately make that much difference." Meanwhile, charities including Save the Children and Amnesty International are urging the UK to welcome thousands of refugees. The Home Office says it's allowing some Ukrainian nationals in the UK to extend their visas.

Not long ago, the current situation seemed unthinkable - even to many who know the region well. So there's a lot to take in. Here's a quick guide to understanding the story. And if you want to dig a little deeper:

The bloodied face of a woman injured in a Russian air strike on flats in Kharkiv looks out from several front pages, as the press reflects on Vladimir Putin's decision to invade Ukraine. "Her blood... his hands," says the Daily Mirror, using an image of the Russian president. The Sun has a variation of the same headline, while the Times - which prints its masthead on a black background - declares it "a dark day for Europe". The Daily Mail predicts Russia will seize the Ukrainian capital Kyiv "in days", while the Daily Telegraph declares a "new cold war". See all the front pages.

A lot has gone on since Tuesday, when people were having simple fun celebrating the palindromic date. Some enjoyed their 2nd - or 22nd - birthday, others chose it as a symbolic date for a wedding, while Google showered searchers with confetti and the message "Happy Twosday 2 you". But one couple perhaps found the perfect way to mark the occasion - by having twins. Here's the story.
And on the subject of a welcoming new additions to the family, a dog who had spent more than 500 days in kennels has finally found a new home. A televised appeal prompted offers from people across the UK and as far afield as the US and Canada who were willing to take in the 10-year-old terrier. And the RSPCA's North Somerset branch say he's settling in nicely with his new owners.
There's more animal magic in this video of two octopuses walking along a Welsh beach - and the story of their rescue. And a rather unusual bear features in our quiz of the week's news. Give it a try.

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