By Sara Sjolin, MarketWatch

LONDON (MarketWatch) -- European stocks market staged broad-based losses on Thursday amid increased political tension in Ukraine, and with a raft of economic data and U.S. Federal Reserve speeches that could add to the volatility.

The Stoxx Europe 600 index fell 0.9% to 334.80, setting it on track for the lowest closing level in a week.

Several prominent companies were among major movers after reporting earnings. Shares of Veolia Environnement SA rallied 7.4% after the French company said it expects revenue to grow in 2014. The news came as the water- and waste-management company reported a net loss in 2013, due to restructuring charges booked during the year.

Shares of Royal Bank of Scotland Group (RBS) slid 7.5% after the majority-state-owned bank posted a loss of 9 billion pounds ($15 billion) for last year and said revenue dropped 12%.

RSA Insurance Group gave up 2.2% after the company launched a GBP775 million rights issue to strengthen its balance sheet. The company reported a sharp decline in operating profit, which is a key measure in the insurance industry.

The broader losses for European markets came as tensions in Ukraine intensified after armed men shot their way into regional government buildings in the country's Crimean region and raised Russian flags early on Thursday.

After the incident, Ukraine's acting president warned that any movements by the Russian military in Crimea, aside from the Russian Black Sea fleet's base in Sevastopol, would be treated as an act of aggression. NATO chief Anders Fogh Rasmussen urged Russia not to take any action that would "escalate tension", according to media reports.

Meanwhile, ousted President Viktor Yanukovych said he still considers himself Ukraine's legitimate president and declared the actions of parliament that stripped him of his powers illegal.

Ukraine's UX index lost 1.5% to 1,103.81, according to the Ukrainian Exchange website. The political uncertainty also weighed on the euro (EURUSD), which fell to $1.3656 from Wednesday's level of $1.3680.

Elsewhere, the data calendar is packed with releases from both Europe and the U.S. In Germany, a report showed the unemployment rate remained at 6.8% in February, but that the number of people out of work dropped by 14,000.

At 1 p.m. in London, or 8 a.m. Eastern Time, inflation data for Germany are out, expected to show annual consumer prices rose 1.3% in February. The numbers come ahead of a highly anticipated euro-zone inflation report on Friday, which could trigger a wider discussion about the need for looser monetary policy from the European Central Bank. Economists worry that continued low inflation may lead to deflation in the region, which would add pressure on the ECB to either cut rates or launch unconventional easing measures at its meeting next week.

Later on Thursday, a reading on durable-goods orders in the U.S. is due, while new Federal Reserve Chairwoman Janet Yellen is set to give testimony to the Senate. Atlanta Fed President Dennis Lockhart, Kansas City Fed President Esther George and Dallas Fed President Richard Fisher are all scheduled to speak on Thursday.

U.S. stock futures pointed to a higher open on Wall Street.

In Europe, France's CAC 40 index fell 0.8% to 4,361.48, Germany's DAX 30 index dropped 1.3% to 9,535.99, and the U.K.'s FTSE 100 index gave up 0.9% to 6,740.14.

Outside the major indexes, Man Group PLC rallied 11% after the investment manager said it swung to a full-year profit in 2013 and laid out plans to repurchase $115 million of its ordinary shares to return surplus capital to shareholders.

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