Story highlights A U.S. official tells CNN that 25 additional heavily armed U.S. Marines arrived at the U.S. embassy in Baghdad on Friday

Concerns have risen since demonstrations occurred there last week in Baghdad's "Green Zone"

(CNN) Twenty-five additional heavily armed U.S. Marines arrived at the U.S. embassy in Baghdad within the last several hours, a U.S. official tells CNN.

The Marines were requested by the State Department, which is in charge of security.

Concerns have risen since demonstrations occurred there last week in Baghdad's "Green Zone," where the embassy is located.

More demonstrations had been expected Friday but the U.S. official said the area has remained peaceful so far.

Neither the Pentagon or State Department disclosed the precise number of security forces already on site.