Intelligence seized from Osama bin Laden's Pakistani hideout suggested that al Qaeda is interested in attacking oil tankers, Homeland Security officials said, a discovery that has prompted the agency to warn industry officials and local law enforcement, The Wall Street Journal reported on Saturday. The warning comes on the heels of indications of continued interest by al Qaeda in attacking other favorite targets, including planes and trains. "In 2010, there was continuing interest by members of al Qaeda in targeting oil tankers and commercial infrastructure at sea," Department of Homeland Security spokesman Matt Chandler said in a statement Friday. He added that "we are not aware of indications of any specific or imminent terrorist attack plotting against the oil and natural-gas sector overseas or in the United States," and said "it is unclear if any further planning has been conducted since mid-last year." Last summer, a Japanese oil tanker was attacked while passing through the Strait of Hormuz, though it suffered only minor damage. Investigators concluded that was a terrorist attack. The materials gathered by U.S. Navy SEALs in the raid earlier this month in Abbottabad, Pakistanincluding Osama bin Laden's personal journalsketched a broad picture of targets the terror group would like to attack, but provided little detail about actual plans to carry out such missions, officials said. The targets revealed so far, including commercial aviation and railroads, have long been in al Qaeda's playbook. Oil tankers and oil-industry infrastructure also have been a preferred target for al Qaeda and associated groups, in keeping with the militants' stated goal of causing economic disruption to the West and to Arab regimes they consider hostile. In 2002, militants used a small skiff packed with explosives to blow a hole in the side of a French-owned oil tanker off the coast of Yemen in 2002. In 2006, al Qaeda tried and failed to blow up a massive oil-processing facility in Saudi Arabia. Four years later, Saudi officials captured more than 100 suspected al Qaeda operatives plotting to attack oil installations. This year, the Saudis began deployment of what will be a 35,000-strong security force to protect the country's oil infrastructure. In Iraq, Islamist militants associated with al Qaeda have repeatedly attacked a key oil pipeline running from the sprawling oilfields in the north of the country toward Turkey, disrupting Iraq's efforts to ramp up oil production and exports. In 2002, al Qaeda considered launching a major attack inside the U.S. by blowing up natural-gas pipelines inside apartment buildings, according to leaked assessments of detainees at the U.S. facility at Guantanamo Bay. Oil tankers and other big ships have another security worry: Piracy in the Indian Ocean. In late 2008, pirates hijacked a Saudi oil tanker loaded with two million barrels of crude, and held it for two months until a multi-million dollar ransom was paid.