我看到的都是说四个人？

cnn

http://security.blogs.cnn.com/2011/09/12/boots-on-ground-libya-but-not-for-combat/

The Defense Department sent in a four-member team to accompany State Department personel returning to Tripoli to assess the damage done to the US embassy since diplomats left earlier this year, a Pentagon spokesman said Monday.

the Washington post
http://www.washingtonpost.com/national/national-security/pentagon-says-4-troops-are-in-libya-helping-state-department-reopen-us-embassy-in-tripoli/2011/09/12/gIQAGnAfNK_story.html?wprss=

Navy Capt. John Kirby, a spokesman for the Joint Chiefs of Staff, said the four military members of the State Department group include two who specialize in disposing of explosives.

关于troops的用法，这有不少人在投诉现在媒体的混用：
http://www.dailywritingtips.com/soldiers-or-troops/

How does a plural word like “troop” become singular?
A Google search indicates that quite a few people are annoyed by this use of the collective noun troop to stand for a single member of a troop.
Using the word troop to stand for one fighting person is a recent phenomenon. The OED added this definition in 1993: