The weekly average prices of the Organization of Petroleum Exporting Countries (OPEC) rebounded slightly to 36.29 U.S. dollars per barrel last week from 34.92 dollars in the previous week due to the currently aggravated Palestinian-Israeli conflict, the Vienna-based oil cartel said on Monday.

    Israel's military operation against Palestinians since Dec. 27,2008 has aggravated the geopolitical tension in the Middle East, which has contributed to the rebound in international oil prices.

    In the four trading days of last week, the OPEC daily oil prices kept increasing, up 4.37 U.S. dollars to 39.95 dollars per barrel on Jan. 2, just before the Israeli army launched a ground attack in Gaza.

    The Israeli army has publicly announced that Israel's ground attack may last for a longer period of time in order to destroy Hamas militants and its leaders.

    Market experts predicted that the continued Palestinian-Israeli conflict together with the recent outbreak of the gas dispute between Russia and Ukraine may further push the international oil prices higher.