Anyone know what was going on with a bunch of unmarked police cars flying down 270 around 8:45 this morning?

I was driving down 270 through Germantown into Gaithersburg around 8:45 this morning and saw probably 10+ unmarked police cars/SUVs with sirens on flying down through traffic and on the shoulder and was just wondering if anyone knows what was going on. They weren't all together like a motorcade, they were spread out like one or two then another one or two a minute later. I got off at Watkins Mill and checked the news briefly when I got to work and didn't see anything, but I have to imagine they were responding to something with how they were driving.