Russian President Vladimir Putin announced the military operation into Ukraine at 5.55am Moscow time - and minutes later the first shelling and missiles were launched into Ukraine, according to reports.
In the capital of Kyiv, an emergency siren has gone off, and pictures show streams of cars clogging up an expressway as people flee the city.
Social media testimonies speak to a growing sense of panic, with some saying they are being rushed into bomb shelters and into basements. Television footage has showed people praying in the streets, huddled in groups.
Guardian journalist Luke Harding in Kyiv says on Twitter that there are few people on the streets, and people are queuing up at cash machines.
Our basement in Kyiv now filling up with families with small children. The kids are holding colouring books. Heartbreaking
— Luke Harding (@lukeharding1968) February 24, 2022