RTE:Oil prices rise as Israel-Gaza fight continues
Benchmark oil for December delivery was up 81 cents to $87.73 a barrel in electronic trading on the New York Mercantile Exchange.
The contract added $1.05 to finish at $86.92 a barrel on Friday.
Brent crude, used to price many international varieties of oil, rose 55 cents to $109.50. It had closed at $108.95 a barrel in London on Friday.
Analysts said that some investors fear that oil supplies could be disrupted if the Israel-Gaza conflict engulfs countries elsewhere in the Middle East, a huge producer of crude.
The fighting comes just as winter arrives in the US and China, at time when energy demands climb.