Benchmark U.S. crude for August delivery was down 32 cents to $102.81 per barrel at 0730 GMT in electronic trading on the New York Mercantile Exchange. That added to a 6 cent decline on Friday to $103.13.
Brent crude for September delivery, a benchmark for international oils, gave up 30 cents to $106.94 on the ICE exchange in London.
Washington announced new sanctions last Wednesday on Russia, including its biggest oil company, over Moscow's support for separatist forces in Ukraine.
On Thursday, a Malaysia Airlines jetliner was shot down in Ukraine, raising concern a possible Western response might disrupt Russian oil exports, but those fears have eased.
Israel's offensive into Gaza intensified turmoil in the Middle East, the world's most important oil-producing region, rattling markets.
In other Nymex trading:
— Wholesale gasoline fell 0.3 cent to $2.838 a gallon.
— Natural gas fell 7.8 cents to $3.873 per 1,000 cubic feet.
— Heating oil gained 0.4 cent to $2.862 a gallon.