The U.S. government is increasingly using bank reports on suspicious transactions to identify Islamic State targets and other terrorist facilities, including determining which refineries to hit with airstrikes, a senior U.S. official said Tuesday.
Information that banks must report to the Treasury Department on suspicious transfers, deposits and other transactions is helping officials identify which terrorist-held oil refineries are the most productive and therefore the best targets, said Kurt Gredzinski, an official with the U.S. Special Operations Command.
Banks and some other firms that handle large amounts of money, including casinos, have long been required to try to keep out dirty money and report potential financial crime to the government. The pressure to adopt adequate anti-money-laundering controls has risen recently as the government has stepped up enforcement and doled out large penalties for violations.
The firms file a total of more than a million reports each year, though they often have little idea whether or how they are used.
"I can't tell you how many times" bank-submitted information has been useful, Mr. Gredzinski said, speaking at a conference for bank anti-money-laundering officers hosted by the American Bankers Association and the American Bar Association.
The Treasury Department's Financial Crimes Enforcement Network collects the bank reports and shares them with other agencies, including the Federal Bureau of Investigation. The Defense Department can access information that other agencies pass on about active investigations, and that program is "gaining traction," Mr. Gredzinski said.
The information can help officials connect the dots on suspicious individuals and help find where they are through their IP addresses, which identify individual computers, when they access their bank accounts, he said.
In the aftermath of this summer's shooting attacks at military sites in Chattanooga, Tenn., a bank reached out to the government within two hours with information about where the shooter had purchased his gun, said Gerald Roberts, the FBI's chief of terrorist financial operations.
At the same panel, Mr. Roberts told bank officers to pay attention to newer types of patterns Islamic State supporters may use. Previous anti-money-laundering efforts focused on large amounts of funds transferred in smaller increments to avoid triggering reporting requirements. But supporters of Islamic State don't need much money to buy a ticket to travel to Turkey, for example, Mr. Roberts said.
The Justice Department has charged dozens of alleged U.S. supporters of Islamic State and other Syria-based terror groups, often focusing on attempts to travel to Turkey to allegedly join the groups.
If an American customer is suddenly using a bank account in Turkey, and then is inactive on the account for a few months only to resurface again later, banks may want to consider reporting it, Mr. Roberts said.
"Some of our best information" on Islamic State facilitation networks can come from banking officials, Mr. Roberts told them.
Write to Aruna Viswanatha at Aruna.Viswanatha@wsj.com