Hundreds of villagers living in a Taliban-controlled area of southern Afghanistan are leaving before a major Nato-led offensive gets under way.
It is expected to be one of the largest counter-insurgency operations since the Afghan conflict began in 2001.
The operation to clear insurgents from the southern town of Marja, in Helmand province, is expected to begin soon.
The UK defence secretary has warned of likely casualties within coalition troops during the offensive.
“Of course casualties are something that we have to expect when we are involved in these operations,” Bob Ainsworth said late on Sunday.
“This is not in any way a safe environment and it doesn’t matter how much kit and equipment we provide for people. We can never entirely make these operations risk-free,” he added.
Operation Mushtarak – which means “Together” in the Pashtun language of southern Afghanistan – is expected to be launched within the next few days.
The British general in overall command of the operation, Maj Gen Nick Carter, said this offensive would be different from previous operations.
In the past coalition forces have driven out the Taliban but then had too few troops to maintain security for the local population.
For the first time, Gen Carter said, Afghan forces would be at the forefront of planning the operation, before being followed up by the introduction of large numbers of newly trained police supported by the coalition.
UK forces ‘soften up’ Taliban targets
At the regional headquarters in Kandahar, commanders are aware of the Afghan police’s sometimes dubious reputation and are preparing to monitor their performance during the operation.
The town of Marja is home to the biggest community under insurgent control in southern Afghanistan
The overall Nato commander in Afghanistan, Gen Stanley McChrystal, said the operation would “send a strong signal that the Afghan government is expanding its security control”.
The forthcoming offensive will be the first major military action since US President Barack Obama announced the deployment of 30,000 extra US troops.
Planning has been under way for weeks, with Nato helicopters dropping leaflets on the area warning residents to leave the area.
Provincial officials said about 35,000 residents of Marja were taking the advice and heading to other parts of Helmand.
One resident, Gul Muhammed, told AFP news agency why he had left town.
“There are Taliban all over the place and foreign troops around Marja,” he said. “So I was scared that we might get hurt.”