New York: More than 12,000 US banks have been put on high alert and security at the three-day World Bank meeting of finance ministers in Washington has been tightened after the Federal Bureau of Investigation (FBI) issued a warning that they could be targets of "unspecified" terrorist attacks.

The FBI said it had received "unspecified information" that "unspecified terrorists" are planning physical attacks against the financial institutions. There are no specific targets nor any specific date.

Among the states covered by the warning include Washington DC, New York, Connecticut, Massachusetts, Virginia, Maryland, Rhode Island, Maine and Pennsylvania.

It was the second warning of its kind made by federal officials this week. The first was prompted by an anonymous telephone call received on April 14 that was later found to be a prank by a 13-year-old boy.

"The decision to disseminate this threat information followed discussions among the FBI, the Department of Justice, the Office of Homeland Security and the Department of the Treasury as part of the national Homeland Security Advisory System," the FBI statement said.

The information was reportedly received from a top ranking al-Qaida leader Abu Zubaydah, now in US custody.

However, unidentified sources were quoted by some reports as saying it could come in the form of a suicide attack.

But the authorities has no way of checking whether the information being given was authentic or not.

PTI