The FBI has added the names of 10 more Chinese nationals to the list of “persons of interest” believed to be connected to a dirty bomb attack that allegedly targets Boston.

Two law enforcement officials, speaking on condition of anonymity because of the ongoing investigation, said the names were part of the same anonymous tip that led authorities on Wednesday to announce that they are seeking to question four other Chinese and two Iraqis.

The officials said the tip remains uncorroborated and there is no credible evidence that such a plot exists.

It was unclear why all the names were not announced at the same time. The officials said there was no new information that led to the addition of the 10 names.

Federal authorities say they are no more worried now than they were later.

Still, I have to wonder if any of these 10 names were connected to the Chinese stowaways found in a cargo ship at the Port of Los Angeles last week. Or is that just a coincidence?