Oil prices rose on Friday as dealers awaited US jobs data and focused on increasing tensions in the Middle East and Ukraine.
US benchmark West Texas Intermediate for delivery in April added 14 cents to $50.90 a barrel.
Brent North Sea crude for April gained 56 cents to stand at $61.04 a barrel around midday in London.
Investors awaited the release Friday of US non-farm payrolls data that, if strong enough, could support a Federal Reserve interest rate increase in the world's biggest consumer of crude.
Analysts expect growth of 240,000 jobs in February and a fall in the unemployment rate to 5.6 percent from 5.7 percent.
"Crude oil prices climbed higher... ahead of the release of the US employment data which will set the tone for today’s trading session," said Myrto Sokou, senior research analyst at Sucden brokers.
Michael McCarthy, chief market strategist at CMC Markets in Sydney, told AFP that traders were "seeing a lot of upside potential, possibly based on tensions in the Middle East and Ukraine."
"Somehow, we are seeing investors looking away from the huge build in US (crude oil) inventories this week," he added.
Libya's National Oil Corporation declared force majeure Wednesday at 11 oil fields after attacks by Islamists.
The OPEC member country has been battling the rise of militias seeking control of its cities and oil wealth since the killing of dictator Moamer Kadhafi in 2011.
Unabated fighting has seen its output reduced from a high of almost 1.5 million barrels a day to 150,000, according to analysts.
In Ukraine, investors are closely watching latest efforts to prop up a ceasefire in the country's eastern region, currently controlled by pro-Russia rebels.
The 10-month conflict in the country -- a key conduit for Russian energy exports to Europe -- is seen as Europe's worse since the war in the Balkans in the 1990s.
Data on Wednesday showed a 10.3 million barrels surge in US crude reserves in the week to February 27, which dampened expectations of robust demand in the world's biggest economy.