Oil prices plunged Monday in New York and London after disappointing economic data in the United States and China, the world's biggest crude oil consumers.
New York's main contract, West Texas Intermediate for May delivery, closed at $88.71 a barrel, down a hefty $2.58 from Friday. Earlier in the day WTI had slumped to $87.86, its lowest level since late December.
Brent North Sea crude for delivery in May tanked $2.72 to settle at $100.39 a barrel in London trade. The European benchmark had flirted with $100 -- a level not crossed since July 12, 2012 -- in early trade.
"The week opened with heavy losses across the oil markets reflecting the current bearish momentum," said senior analyst Myrto Sokou at the Sucden brokerage in London.
"The recent Chinese economic data failed to meet analysts' expectations and added further pressure to the market that was already showing sharp losses following disappointing US economic data last week."
China's gross domestic product growth slowed to 7.7 percent in the first quarter of this year from 7.9 percent in the prior quarter, the government said, well below the 8.0 percent GDP growth forecast in a poll of 12 economists by AFP.
Sokou said the Chinese data renewed concerns about another possible slowdown in Chinese demand for both oil and metals.
The news raises questions about the strength of the world's number-two economy, which is a key driver of global growth, analysts said.
In the United States, April data showing a larger-than-expected slowdown in New York state manufacturing and a drop in confidence of US homebuilders also weighed on the oil market.
"The early indications are that April economic data remain soggy relative to a disappointing March," said Deutsche Bank analysts in a research note.
Prices have been under pressure after forecasts last week of lower global demand by the Organization of Petroleum Exporting Countries, the International Energy Agency and the US government's Energy Information Administration.