Brent crude oil prices slid to a four-month low on Thursday as Japanese stimulus measures and poor US jobless claims data dented sentiment on the eve of vital non-farm payrolls figures, dealers said.
London's Brent North Sea crude for delivery in May dived as low as $105.44 per barrel in afternoon deals. It later stood at $105.92, down $1.19 from Wednesday.
New York's main contract, West Texas Intermediate (WTI) light sweet crude for May, sank $1.83 to $92.62 per barrel.
Prices dipped following aggressive stimulus measures from the Bank of Japan and an unexpected jump in US unemployment claims.
The Bank of Japan's fresh raft of monetary easing measures sent the yen tumbling against the dollar and the euro. The stronger greenback makes dollar-priced crude more expensive for buyers using weaker currencies, hitting oil demand and prices.
In another blow, initial US jobless claims -- an indicator of the pace of layoffs -- totalled 385,000 in the week ending March 30, up 28,000 from the prior week's reading, official data showed.
The unexpected increase in claims came on the heels of a disappointing report Wednesday on private-sector hiring.
On Friday, the Department of Labor will release its closely-watched monthly nonfarm jobs and unemployment report.
"Crude oil extended its losses today as the dollar rallied on massive yen selling after the Bank of Japan delivered the shock and awe message in its colossal battle to end deflation," said GFT Markets analyst Fawad Razaqzada.
Meanwhile, the European Central Bank on Thursday held record-low eurozone interest rates at 0.75 percent.
Razaqzada added: "ECB chief Mario Draghi said the ECB cannot replace the lack of capital in Europe's banks or compensate for any lack of action by governments.
"However, by far the biggest reason behind today's selling was concerns about rising supply of oil and faltering demand.
"Today's main US data release -- the weekly unemployment claims figure, which showed an unexpected rise -- did not help to dispel those fears. A truly bad NFP number tomorrow could really put the nail in the coffin."
Oil had already slumped by about $3 a barrel on Wednesday after the US Energy Information Administration revealed that US crude reserves rose 2.7 million barrels to 388.6 million barrels.
That was almost double market expectations for an increase of 1.5 million barrels.
Surging US inventories signal weaker demand and tends to put downward pressure on prices.
A pipeline closure ExxonMobil's Pegasus pipeline in Arkansas, a 95,000 barrel-a-day line, has also sparked fears of a build-up of stockpiles at the Cushing, Oklahoma, which is a key delivery point.