FBI and Immigration and Customs Enforcement agents on Thursday morning executed search warrants in "several locations in the Northeast," a statement from ICE said.

At least two raids were in Boston suburbs, where two of the men were arrested. The third man was arrested in Maine, while search warrants related to the case were also executed in Camden County, N.J., and on Long Island in New York.

Attorney General Eric Holder said late Thursday that the three men are connected to Faisal Shahzad, the 30-year-old Connecticut man who allegedly drove a car bomb into Times Square on May 1. But, Holder said, the exact nature of those connections is still unclear.

"There's at least a basis to believe that one of the things that they did was provide him with funds," Holder said...

...The source said the New England men, all three from Pakistan, may have "unwittingly assisted in some capacity." In fact, the source said, Shahzad may have duped the men into providing money, but authorities are not ruling out anything at this point.

Authorities are looking at whether Shahzad may have used a "hawala" system to obtain funds for his bomb plot. According to the Justice Department, a "hawala" is an informal "value transfer system" in which money does not pass through the banking system. Instead, funds are transferred to an operator in one country, and corresponding funds, less any fees, are sent to recipients in another country...

...The New England men have been arrested on "administrative charges," which means federal authorities will not advise them of Miranda rights to question them, as is required in criminal cases...

...One of the men arrested near Boston on Thursday has been charged with overstaying his visa, and the other, identified as Pir Khan, was already the subject of proceedings to remove him from the country, according to one source.

The third man was arrested in Maine, also allegedly for overstaying his visa, a source said...