U.S. soldiers arrive at an Afghan National Police checkpoint in Helmand province.
(Creative Commons)

U.S. and Afghan troops clashed with Taliban snipers, who fought solo or grouped with others in guerilla-style ambushes, for more than four hours Wednesday during the fifth day of an attack intended to eradicate Taliban insurgents and reestablish local government services.

The drastic increase in sniping came less than 24 hours after 5,000 troops secured the central police station in Marja, a city in southwestern Afghanistan's Helmand Province, long described as the last main Taliban stronghold.

The town of about 85,000 people has recently developed into a Taliban encampment plagued with drug trafficking and bomb factories and houses anywhere from 400 to 1,000 hardcore insurgents. 

Operation
Moshtarak , which means "together" in local dialect Dari, is billed as
one of the largest battles in the war and the largest allied offensive
since Operation Enduring Freedom in 2001.

One Marine has died since the attack began. There is no authoritative count on how many militants have been killed.

Afghan President Hamid Karzai approved the offensive just hours before it began and asked the assault force to exercise "absolute caution to avoid harming civilians."

On Sunday, 12 civilians were killed in a rocket strike
when coalition troops aiming for a compound containing Taliban
insurgents missed their target by 300 yards, instead striking a
civilian compound, NATO officials said.

Monday, a patrol of NATO soldiers spotted
what it mistakenly thought was a group of insurgents planting bombs in
Kandahar province and called in an air strike. Five civilians were
killed and two were injured.

Although commanders expect the fighting to end within days, Brig. Gen. Larry Nicholson told ABC News that it may be a month before the area is cleared of remaining insurgent threats.

The
offensive is the first major operation involving U.S. troops since
President Obama deployed 30,000 more soldiers to Afghanistan late last
year

Retired Marine Gen. James L. Jones, Obama's national
security adviser, said on CNN that the operation  "is going to make a big change in
not only the southern part of Afghanistan, but will send shock waves
through the rest of the country that there is a new direction, there's
a new commitment."