We have dispatched additional Marine security to South Sudan:
President Barack Obama said on Friday the United States has deployed 45 military personnel to volatile South Sudan to protect the embassy and U.S. government employees there.
I assume this means Marines since they have both duty for regular security and have rapid reaction forces designed to reinforce diplomatic facilities.
I also assume this is related:
Rebel fire hit two U.S. military aircraft responding to the outbreak in violence in South Sudan on Saturday, wounding three U.S. service members and heavily damaging at least one of the aircraft, officials said.
One is in critical condition, it is said. The aircraft involved were V-22 Ospreys, the helicopter/plane craft that is mostly used by our Marines (but I think Army special forces use them, too, if memory serves me).
UPDATE: Here's a story on one of those FAST (Fleet Antiterroristm Security Team) platoons in action a year ago.