It’s not much, but it’s what we have so far:

Police took a 20-year-old Saudi national into custody near the scene of yesterday’s horrific Boston Marathon bomb attack, law-enforcement sources told The Post.

The potential suspect was questioned by the FBI and local police yesterday at Boston’s Brigham and Women’s Hospital, where he was under heavy guard while being treated for shrapnel injuries to his leg sustained in the blast.

In late afternoon, a large group of federal and state law enforcement agents raided an apartment in a building in the Saudi man’s hometown of Revere, Mass.

FBI agents could be seen through one window. It was not clear what, if anything, they found. But Revere fire officials said they were called out to support bomb-squad officers as part of an investigation of a “person of interest” in the marathon attack

If I’m reading the timeline correctly, officials began searching the apartment at 5:30 yesterday evening, and had not yet released the POI as of 2:35 this morning when the story was last updated.