European stocks plunged 3% on Thursday as investors dumped riskier assets after Russia attacked Ukraine, raising fears that a war in Europe will fuel higher inflation and derail economic growth.

The pan-European STOXX 600 index fell 2.9% - hitting its lowest since May 2021 while marking a correction or 10% decline from its January record high.

The German DAX fell 3.7% to March 2021 lows, bearing the biggest brunt of the sell-off on fears over the country's heavy reliance on energy supplies from Russia.

Oil crosses $100 for first time since 2014 on Ukraine attacks

A surge in oil prices helped limit losses on the UK's commodity-heavy FTSE 100, which fell 2.4%.

Russian forces fired missiles at several cities in Ukraine and landed troops on its south coast on Thursday, officials and media said, after President Vladimir Putin authorised what he called a special military operation.

The United States and its allies will impose "severe sanctions" on Russia, US President Joe Biden said.

Europe's oil & gas index fell the least among sectors, down 1.2% as oil prices surged about 6%, pushing Brent crude past $100 a barrel for the first time since 2014.

European banks most exposed to Russia including Austria's Raiffeisen Bank, UniCredit and Societe Generale dropped between 5% and 6.6%, while the wider banking index fell 4.2%.

Russian ground forces cross into Ukraine: Kyiv

Technology and travel & leisure were among the other top decliners. Futures tracking New York's S&P 500 fell 2.0% and the tech-heavy Nasdaq 100 dropped 2.6%.