they were patrolling for black marketeers so they could get there cut
It's a long time ago but not much changed. On a 3 day pass in WW II I sold my cigarettes to pay for my stay. I didn't smoke and cigarettes were cash. Black market very active but they didn't know the difference between our money and cigar store coupons. They wanted GI overcoats. The Red Cross gave us passes to the Follies and used our cash for Pig Alley and got drunk. Most of the French soldiers I saw were Algerians. The guys were more afraid of them than the Nazis. They carried ears like Indians carried scalps. I don't know whether they were Muslims or not, frankly it didn't make any difference what they were.