* Al Qaeda attack on major oil facility stopped
* Violence surging as insurgents step up bombings
By Ahmed Rasheed
BAGHDAD, May 30 (Reuters) - Iraq foiled an al Qaeda plot touse tanker trucks packed with explosives to attack a key Baghdadoil facility, a senior security official and oil sources said.
The security official declined to name the facility becausethe investigation was underway but oil ministry officials saidthe security forces were on high alert following a spate ofattacks on a northern pipeline.
Protecting infrastructure for the world's fourth largest oilreserves is crucial for Iraq as it rebuilds an industry batteredby years of war following the 2003 U.S.-led invasion andsanctions against former ruler Saddam Hussein.
"We have arrested a key local leader of al Qaeda whoorganised the plan to launch a major attack against a large oilfacility in Baghdad," a senior anti-terrorism official said.
The security source said insurgents planned to packexplosives into tankers transporting crude oil from southernBasra oilfields to the main oil storage depots inside the majoroil facility of Baghdad, where the bombs would be detonated.
"They were planning to put in explosives and booby-trap morethan one oil tanker," he said.
Baghdad oil facilities include the large Doura refinery,East Baghdad oilfield, which currently has limited production ofaround 10,000 barrels per day to feed Doura, and a gas facilityjust north of the capital.
Militants often target security forces, and Shi'ite andSunni mosques, but attacks on major oil sites beyond pipelinebombings are rarer.
A key pipeline from Iraq's northern oilfields around Kirkukto the Turkish port of Ceyhan has been repeatedly attacked bymilitants over the last month.
Gunmen attacked a gas field operated by Korea Gas Company inApril, killing three local contractors.
Violence has spiked since the start of the year as alQaeda's local wing, the Islamic State of Iraq, and other SunniIslamist insurgents stepped up attacks to try to stoke awidescale sectarian conflict.
Iraq expects to boost its oil output to rival the level oftop producer Saudi Arabia after awarding some of its mostattractive oilfields to global oil companies, including BP, Shell and Exxon Mobil.