**US forces are facing fierce resistance around the Taliban stronghold of Marjah as a major Nato offensive in southern Afghanistan moves into its fourth day.**The progress of US troops has been hampered by sniper fire and improvised explosive devices (IEDs) in some areas.
British and Afghan troops are reported to be advancing more swiftly in the nearby district of Nad Ali.
A Nato spokesman said they have begun setting up joint patrol bases to provide a permanent security presence.
Unrelated to the Marjah offensive, an airstrike in neighbouring Kandahar province killed five civilians who were mistakenly believed to have been planting roadside bombs.
The deaths come after two US missiles struck a house on the outskirts of Marjah on Sunday, killing 12 people, half of them children.
Nato has stressed that the safety of civilians in the areas targeted is their highest priority.
Insurgent attacks
On Monday, Afghan Gen Aminullah Patiani told AFP news agency that “almost all” of Marjah and Nad Ali were under the control of US and Afghan forces.
Civilians die in Kandahar strike
“The Taliban have left the areas, but the threat from IEDs remains,” he said.
Despite Afghan government claims that the insurgents were on the run, Taliban fighters stepped up attacks against US Marines and Afghan soldiers in Marjah.
Small teams of insurgents repeatedly attacked troops and mine-clearing vehicles with rocket, rifle and rocket-propelled grenade fire.
US Marines have twice unsuccessfully tried to clear a bazaar area in Marjah of enemy positions.
Marjah resident Haji Mohammed Jan told the BBC the Taliban had tried to stop people leaving, but he and others had managed to escape.
Dawud Ahmadi, a spokesman for Helmand’s governor, said nearly 1,000 displaced families had arrived in the provincial capital, Lashkar Gah.
Operation Moshtarak, meaning “together” in the Dari language, is the biggest coalition attack since the Taliban fell in 2001.
The operation is also considered the first big test of US President Barack Obama’s new “surge” strategy for Afghanistan.
Allied officials have reported only two coalition deaths so far - one American and one Briton killed on Saturday.
Two other Nato soldiers died on Monday in unrelated bomb strikes in Helmand, military spokesman Sgt Kevin Bell said.
Afghan officials said at least 27 insurgents have been killed so far in the offensive.