European stocks have fallen sharply as concerns about a trade war and higher US bond yields have stoked concerns among global investors.

In London, the UK's FTSE 100 share index fell 1.7% to 7,023.

Markets in Asia had plunged to a 19-month low after US shares suffered their worst losses in eight months.

US President Donald Trump called the falls a "correction", but said the Federal Reserve, which has been raising interest rises, had "gone crazy".

The global sell-off came as International Monetary Fund head Christine Lagarde said stock market valuations have been "extremely high".

In Paris, the Cac 40 share index was down 1.7% at 5,119 points, while in Frankfurt the Dax index fell 1.3% to 11,559.

The FTSE 100 and the Cac 40 have fallen to their lowest levels since April, while the Dax is at its lowest since early 2017.

Markets in Asia had followed US stocks, which slumped on Wednesday.

Japan's benchmark Nikkei 225 dropped 3.9%, its steepest daily drop since March. In China, the Shanghai Composite fell 5.2% to its lowest level since 2014.

Trump attacks 'crazy' Fed
US markets have done better than expected this year, bouncing back after turmoil early in the year to set new records over the summer.

But the Federal Reserve is raising interest rates, with the latest hike coming last month, and more increases are likely to come.

The Fed last month abandoned its description of its policy as "accommodative", reflecting a view that the economy is strong enough not to need the kind of stimulus it received in the after-math of the financial crisis.

The prospect of dwindling US stimulus has been compounded by a trade war between the world's two largest economy - which the IMF has warned could harm growth.

US President Donald Trump has been particularly critical of the Fed's rate rises, breaking with tradition in the US where presidents are expected to respect central bank independence.

"The Fed is making a mistake," he told reporters on Wednesday. "I think the Fed has gone crazy."

Correction 'well-overdue'
However, analyst Michael Hewson of CMC Markets said it was "too simplistic just to blame the Federal Reserve" for market turmoil.

"There are a number of factors," he told the BBC. "Obviously, concerns about slowing growth - the IMF downgraded its global growth forecast for the global economy, citing emerging market concerns," he said.

Mr Hewson added that trade tensions between China and the US had weighed on Asian markets for most of this year, while trade tensions between the US and the EU had hit European markets. Concerns about the political situation in Italy were also adding to market nervousness.

"It's a well-overdue correction, driven by US markets, which have out-performed for most of the past two to three years," he added.

Simon French, chief economist at Panmure Gordon, told the BBC that what was "really quite interesting is the speed with which the sell-off is taking place", adding that there has been a pattern over the past few years of markets hitting new highs followed by sharp drops.

He added: "When you've got the president of the US saying some quite unpleasant things about the Federal Reserve... you don't necessarily expect it in the US."

"That's made investors say 'Given those gains, we'll bank some of them, [and] take money off the table'."