Oil prices fell on Friday after a massive earthquake shook Japan, shutting refineries and other industrial facilities in the world's third-largest oil consumer and triggering a broader sell-off in commodities.
Muted protests in Saudi Arabia were a relief to investors addled by plans for demonstrations in the world's top oil exporter with markets already reacting to the battle for Libya that has curbed production and exports.
US heating oil, the benchmark distillate contract, and gasoline futures slipped, but had some support from expectations that Japan's shut refineries and nuclear power plants will require more fuel imports.
Brent crude futures for April delivery fell $1.91 to $113.52 a barrel at 2:53 p.m. EST (1953 GMT), having fallen as low as $112.25.
US crude futures for April delivery fell $1.54 to settle at $101.16 a barrel, after earlier falling to $99.01.
US crude posted a 3.12 percent loss for the week, its first weekly loss in four.
The US front-month heating oil crack spread, or refining profit margin, rose 83 cents to $26.01 a barrel, while the gasoline crack spread rose 19 cents to $24.31.
"From an oil pricing perspective, the situation in Japan is likely to result in a negative impact on crude oil prices and a positive for refined products," said Dominick Chirichella, senior partner at the Energy Management Institute in New York.
Japan was hit by a magnitude 8.9 earthquake, the largest since observations began in the late 19th century. A security clampdown in Saudi Arabia's capital kept a lid on a planned day of rage.
Police in Kuwait fired tear gas to break up a demonstration and Bahraini police blocked several thousand protesters from reaching the royal palace as the region continued to deal with spreading unrest.
Tens of thousands of protesters marched in Yemen's capital and protests turned violent in the southern port city of Aden.
Fighting continued in Opec-member Libya. Rebels repelled a counter-offensive by leader Muammar Gaddafi's forces, but appealed to foreign powers to impose a no-fly zone to stop further attacks.