Oil prices tumbled in Asia Tuesday, with Brent falling below $100 a barrel, on demand fears after Chinese growth data indicated a pick-up in the world's number two economy remained fragile. New York's main contract, light sweet crude for delivery in May dropped $1.04 to $87.67 a barrel, while Brent North Sea crude for May shed $0.99 to $99.64 in the afternoon. Brent is below $100 for the first time since July. "The market is mainly still reacting to the poor GDP numbers out of China, which has reaffirmed the trend that the world's second-biggest economy is slowing," David Lennox, resource analyst at Fat Prophets in Sydney, told AFP. Growth in China eased to 7.7 percent in the first quarter, data showed Monday, below forecasts for 8.0 percent. "Many had called the bottom for China's economy and with Europe languishing with low growth many had pinned consumption and demand to be driven by China," Jason Hughes, head of sales trading at CMC markets in Singapore, wrote in a note. "This now seems to be perhaps a bit too optimistic." The market was also weighed by disappointing data from the United States, analysts said. April data showed a larger-than-expected slowdown in New York state manufacturing and a drop in confidence of US homebuilders. Oil 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.