"Several U.S. commanders suggested the insurgents had learned the tactics in recent weeks from skilled guerrilla commanders from outside the city, perhaps led by foreign fighters who came to Iraq to fight the occupation."
Chechens?
"For the past several weeks, Bullimore has been sending sniper teams into the city to kill insurgents planting roadside bombs under cover of darkness. The bombs, made of artillery shells or tank rounds and detonated by remote control, have ravaged his soldiers as they move along main supply routes.
Late Wednesday night, Grider, the platoon leader, worked with a sniper team in the Tahrir district, just south of the government center. Overlooking Canal Street, a main avenue through the city of 250,000 people, the sniper on the team fired on two men setting bombs. Grider said both fell dead -- the fourth and fifth of the week."
Sounds like it could be!
These terrorists were much better organized and discipled.