With more than 60,000 Iraqi army soldiers, 78,000 Iraqi policemen and over 8,700 border patrol officers, the U.S. military said Friday it planned to send soldiers from the 4th Brigade, 1st Infantry Division back to Fort Riley, Kan.

A U.S. military statement noted a marked increase in the numbers of the Sons of Iraq force active in the northern Iraqi provinces, up 25,000 from 14,500 at the beginning of 2008.

Those numbers contributed to a drop in violence in Iraq of over 60 percent in the past 10 months, the U.S. military said.

The activity of Iraqi forces is evident in the discovery of a weapons cache in Mahmudiyah, about 25 miles south of Baghdad.

A joint Iraqi-U.S. operation uncovered a weapons cache consisting of several large-bore mortar rounds, several rocket-propelled grenades and two Katushya rockets.