Authorities investigating the bombing of a military recruiting center in Times Square have turned their attention to a strange incident at the Canadian border last month.  Four men fled a checkpoint when crossing, and the Canadians arrested two of them.  During questioning, pictures of the center and other apparent targets were found in their backpacks, suggesting a plot in the works:

Nearly a full day after the explosion in Times Square, law enforcement officials said they had no suspects. WNBC.com has learned NYPD, Homeland Security and FBI officials are now revisiting an incident that occurred along the Canadian border last month, concerned there might be a possible connection to the Times Square explosion.

Four men trying to cross the border attempted to flee the checkpoint as Canadian officials tried to question them, investigators said.

Two of the men got away, officials said. The men left behind a backpack with photos of various New York City locations including Times Square, according to sources speaking on condition of anonymity. One of the photos included the military recruitment center, officials said. As a precaution, NYPD outreach officers last month went to various New York City businesses, including the Times Square military recruitment center, to investigate if there had been any specific threats. No threat information was known at the time, a law enforcement source said. …

One law enforcement official described two of the men are believed to be “anarchist-types.” He stressed as of now there is nothing to link the men to Thursday’s explosion. But it is a prudent to follow this possible lead, he said.

The investigators have played down two other theories over the last few hours.  This bombing had certain similarities to recent attacks on the Mexican and British consulates, but also significant differences.  Those two bombings used identical explosive devices based on black powder in dummy grenades, while yesterday’s attack used a different type of IED without grenades.

Also, the FBI announced that it has questioned a “person of interest” in the letters sent to several Congressmen that included a picture of the recruiting center.  They have also begun backing away from a connection between that and the bombing for a couple of reasons, mainly that the manifesto had the name and/or signature of the person who wrote it.

More developments will certainly be forthcoming today.  Keep checking back to this post for updates. Meanwhile, for those who downplay violence and intimidation against recruiters, Michelle has a nice, long timeline of the escalation.  I’m not naming names … cough cough ….