European economic and security concerns pushed crude oil prices higher early Friday after overnight losses brought on by weakness in China.

French Prime Minister Manuel Valls called for a state of national mourning after what's being described as a terrorist attack on Bastille Day left 84 people dead.

There have been no claims of responsibility after a lorry driver rammed his vehicle into a crowd on a main street in Nice. The driver also fired on the crowd along a 1.3 mile parade route before being shot dead by police.

The attack follows the November coordinated siege on Paris claimed by the group calling itself the Islamic State and comes at a time when the French economy is coping with what the International Monetary Fund described as "lackluster" employment prospects.

The price for Brent crude oil moved up 0.6 percent early Friday to $47.64 per barrel. West Texas Intermediate, the U.S. benchmark price for oil, gained 0.4 percent from the previous close to start the trading day in New York at $45.87 per barrel.

Oil has been volatile this week, moving in fits and starts in response to energy sector activity and economic data. The rally Friday was supported further by a declaration from Exxon Mobile that it couldn't honor its contractual commitments in Nigeria, which according to Bloomberg News may be a response to militant activity in the Niger Delta.

Meanwhile, Eurostat, the European Union's data-gathering office, reported inflation in EU was flat in June, up from a negative 0.1 percent rate in May, but down from the 0.1 percent increase recorded in June last year.

Oil prices moved in negative territory in overnight trading after the National Bureau of Statistics of China reported that "complicated domestic and external conditions" meant the country struggled with mounting economy pressure during the first half of the year.

Chinese growth concerns pushed oil prices and global stock markets sharply lower to start 2016. Last month, U.S. Federal Reserve Chair Janet Yellen told lawmakers that factors like China's stagnation and concerns about slow productivity growth were creating "headwinds" for future U.S. economic growth.

Oil prices resume decline on supply build
Washington (UPI) Jul 13, 2016 - Crude oil prices reversed direction in early Wednesday trading to move lower after a report found a net increase in global crude oil supplies.

Oil has been volatile in recent sessions, with a decline Monday sparked by reports of higher production from members of the Organization of Petroleum Exporting Countries, only to be followed by a major rally Tuesday sparked by OPEC's report of evaporating inventories of oil.

The International Energy Agency reported Wednesday global crude oil supplies recovered to 96 million barrels after outages, largely in Canada, eased. Global commercial inventories, meanwhile, ended May at a record high.

"Preliminary information for June suggest that stocks in the Organization for Economic Cooperation and Development added a further 900,000 barrels while floating storage has continued to build, reaching its highest level since 2009," the IEA said in its monthly report.

An increase in U.S. oil production helped pushed markets heavily toward the supply side during the height of the shale era, pulling oil prices well below the level of $100 per barrel common in 2014. In the wake of the IEA's report, the price for Brent crude oil fell 1.4 percent to $47.80 per barrel. West Texas Intermediate, the U.S. benchmark price, lost 1.1 percent to start trading in New York at $46.29 per barrel.

Global markets are starting to shake off the immediate panic sparked by a June decision by British voters to leave the European Union. A report from the International Monetary Fund finds the U.S. economy may be something of a safe haven for investors, though the U.S. economy itself has lost momentum because of lower oil prices and a strong dollar.

For Europe, Adam Sieminski, the administrator for the U.S. Energy Information Administration, the so-called Brexit may weigh on European demand for oil.

"The United Kingdom's decision to leave the EU could lead to a drop in European oil consumption if there is a reduction in business investment and consumer spending," he said in an emailed statement.

In an assessment on the French economy, meanwhile, the IMF said recovery was strengthening in the wake of the recent recession, though growth was subdued and job creation has been "lackluster" as unemployment hovers around 10 percent.