Crude oil prices held to less than $88 per barrel Wednesday but headed higher in a week with trading heavily influenced by tension in the Middle East. Israel held off on launching a ground attack on the Gaza Strip Tuesday, which allowed prices to ease back. With a bus bomb wounding at least 21 people in Tel Aviv Wednesday, how the friction between Israel and the Palestinians will abate is unknown. On the New York Mercantile Exchange, West Texas Intermediate crude oil prices headed higher, adding 72 cents to reach $87.47 per barrel. Reformulated blendstock gasoline added 3.33 cents from Tuesday to $2.7217 per gallon. Home heating oil prices added 3.24 cents to $3.0807 per gallon. Natural gas prices shed 0.5 cents to $3.827 per million British thermal units. At the pump, the national average price of unleaded gasoline rose to $3.426 per gallon from Tuesday\'s $3.412, AAA said.