The European Central Bank lifted its key interest rates by a surprise 50 basis points on Thursday, its first hike since 2011 and more than expected, as it attempts to curb soaring inflation in the eurozone.

Economists polled by Reuters had predicted a 25 basis point increase.

The ECB raised its benchmark deposit rate by 50 basis points to zero percent as it joined global peers in jacking up borrowing costs. The rate on the main refinancing operations climbs to 0.50 percent and on its marginal lending facility to 0.75 percent.

The rate increase will be effective from July 27, while future hikes "will be appropriate," according to the ECB.

Eurozone inflation rose to 8.6 percent in June from 8.1 percent in May, above the ECB's 2 percent target.

"The Governing Council's future policy rate path will continue to be data-dependent and will help to deliver on its 2 percent inflation target over the medium term," the ECB said in a statement.

The ECB also agreed to provide extra help to the 19-country currency bloc's more indebted nations, approving a new bond purchase scheme called Transmission Protection Instrument, intended to cap the rise in their borrowing costs and limit financial fragmentation.

(With input from agencies)