The Loop: Russian invasion of Ukraine begins, Clive Palmer hospitalised with COVID symptoms, Test great Rod Marsh suffers major heart attack

Hello. It's Thursday, February 24 and you're staying in The Loop with this quick wrap of today's news headlines.

Today's biggest story: The Russian invasion of Ukraine has begun

Russia launched an invasion of Ukraine, moments after President Vladimir Putin appeared on television to say he had authorised a military operation in the Donbas region.

Ukrainian President Volodymyr Zelenskyy has declared martial law and Australian Prime Minister Scott Morrison says there are unconfirmed reports of casualties in the "hundreds" already.

Vision has emerged of traffic jams backed up for kilometres as people try to leave the capital of Kyiv.

The situation is moving incredibly quickly. You can follow developments as they happen in our live blog.

What else is going on

• United Australia Party chairman Clive Palmer is being tested for COVID-19 after being taken to a Queensland hospital via ambulance with symptoms
• A total of 18 businesses in the WBHO Australia Group, including construction giant Probuild, have been placed into administration
• Former Australian Test cricketer Rod Marsh is in a critical condition in a Queensland hospital after suffering a heart attack

News alerts you might have missed

• The Australian share market has had its worst day in almost 18 months after Russia invaded Ukraine. Oil prices have hit a fresh seven-year high
• The body of a motorcyclist has been found after he went missing in floodwaters near Gympie. More severe weather is forecast for later today
• A cyclone watch has been issued for a stretch of coast between the NT and WA, with the chance of a category two storm forming near Darwin

If you haven't already, download the ABC News app and turn on notifications for the news topics you're most interested in.

What Australia has been searching for online

• Manchester United. After a tepid start, United came from behind the snatch a late 1-1 draw with Atlético Madrid in the Champions League thanks to young academy product Anthony Elanga
• Locky Gilbert. There's been some drama on the latest episode of SAS Australia, with actor Pauly Fenech reportedly threatening to "smash" the former Survivor competitor and Bachelor despite their almost 50-centimetre height difference
• Anna Karen. Tributes are pouring in for the 85-year-old EastEnders and On the Buses actor who has died in a house fire

You're up to date

Thanks for joining us.

ABC/wires