Marjah, Afghanistan (CNN) -- The NATO operation aimed at tackling a Taliban stronghold in southern Afghanistan is making progress, officials say. Operation Moshtarak, in the southern city of Marjah, is going "very smooth" so far, U.S. Marine Corps Lt. Col. Mark Dietz told CNN Monday. He said the Marines had bypassed several lines of roadside bombs and were in the process of clearing the city "from the inside out." There has been some active combat, said CNN's Atia Abawi, who is embedded with U.S. Marines in Marjah. Watch Marines in action in Marjah The Taliban is "popping up in various parts of the city," Abawi said. "We went just a couple hundred meters outside of the position that we're usually based in -- we were under gunfire ourselves."
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NEW: Marines clearing Taliban's "last bastion" in area from inside out, spokesman says
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NEW: Anti-Taliban operation's progress is "very smooth," U.S. military says
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NEW: Five Afghan civilians killed in airstrike not connected to Operation Moshtarak
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Troops in Marjah recovered $8.7 million worth of raw opium, says embedded CNN reporter
The @placeholder finances its activities in part through the illegal opium trade.
The @placeholder has often inflated casualty figures in the past.