Crude oil futures settled higher on both sides of the Atlantic Friday, reversing early losses and finishing a volatile week on an upbeat note.
Volume was thin amid a lack of market-moving news, but renewed concern about tight supplies coupled with positive technical signals prompted traders to cover short positions.
At the New York Mercantile Exchange, nearby June crude gained US$0.40 to close at US$29.14 a barrel, near its intraday high of US$29.20 a barrel. The contract had fallen as low as US$28.62 a barrel earlier in the session.
Oil prices started the week on a negative note but advanced nearly 5 percent this week after the government reported an unexpected decline in crude inventories.
After a pullback Thursday amid light profit taking, crude prices look technically bullish again, some analysts and traders said.
June heating oil futures finished up 52 points at US$0.7556 a gallon (US$0.198 a liter).
Meanwhile, June gasoline futures rose 117 points to end at US$0.8790 a gallon (US$0.2313 a liter).
At London's International Petroleum Exchange, the new front-month July contract advanced US$0.38 to close at US$26.10 a barrel.
On the news front, fear of new terror attacks in Saudi Arabia, as well as the status of Nigerian oil supplies kept petroleum traders jittery ahead of the weekend.
The US Department of State late Thursday warned of a possible terrorist attack in the Saudi city of Jeddah
The warning came just two days after deadly attacks in Riyadh, Saudi Arabia.
Meanwhile in Nigeria, Royal Dutch/Shell Group's local unit, Shell Petroleum Development Co, has extended its force majeure on Nigerian Forcados crude loadings until June 4, a Dutch/Shell spokesman said Friday.
Royal Dutch/Shell's force majeure was previously scheduled to be lifted May 22.
The delay is due to the recent political unrest in Nigeria, and isn't connected to the damaged Forcados pipeline.
Royal Dutch/Shell was able to complete repairs of the Forcados pipeline on Tuesday, the spokesman added. The spokesman was unable to give current production levels.
Shell had shut in around 150,000 barrels a day of Forcados due to the unrest. Normal production is 440,000 barrels a day.