Late this afternoon, reports surfaced that the US has now flown a B-52 bomber over or least "near" the islands. Here's Reuters with more:

A U.S. B-52 strategic bomber flew over Chinese manmade islands in the South China Sea recently and was contacted by Chinese ground controllers but continued its mission undeterred, the Pentagon said on Thursday.

"We conduct B-52 flights in international air space in that part of the world all the time," Pentagon spokesman Peter Cook told a briefing. "My understanding is there was one B-52 flight, I'm not even sure the date on it, but there was an effort made by Chinese ground controllers to reach out to that aircraft and that aircraft continued its mission. ... Nothing changed."

And here's a more colorful account from The Hill:

The United States flew two B-52 bombers over the weekend near man-made islands constructed by China in the South China Sea, a U.S. official tells The Hill, in a clear challenge to China's territorial claims to the area.

The bombers made one pass within 12 nautical miles of the islands, the official said, in what the military refers to as a "freedom of navigation" operation.

During the operation, the Chinese military radioed the bombers, telling them to "get away from our islands." The bombers did not comply, according to the U.S. official. 

Questioned by The Hill about the official's account, Pentagon press secretary Peter Cook on Thursday confirmed that a B-52 incident with China near the islands took place, but declined to say when.

Pentagon spokesman Navy Cmdr. Bill Urban later said the B-52s did not get within 12 miles of the man-made islands, and called the flight part of "routine operations."

As The Hill goes on to note, and as we reported earlier this week, this comes as China sends J-11BH/BHS fighter jets to Woody Island, south of Hainan in what one could be forgiven for believing is an attempt to discourage US military flyovers. 

US military flyover like the one described above.

So there you have it, the latest escalation in what frankly is becoming an increasingly dangerous (and largely uneccesary) game of chicken.

We'd also note that the US has expressed its intention to conduct the destroyer operations twice per quarter, so one wonders how many times the B-52s will be flying over "near" the islands.