A major offensive on Taliban strongholds has been launched by Afghan security forces, supported by British troops.

Among those overseeing the Afghan-led operation launched on Friday in the area surrounding Helmand's second city of Gereshk were members of 3rd Battalion the Yorkshire Regiment.

The regiment lost five soldiers in a blast which killed six while they were travelling in an armoured vehicle about 20 miles away two weeks ago.

The operation - dubbed Now Roz, meaning New Day in Dari - aims to rid the Taliban from an area which is traditionally regarded as a stronghold for the insurgency.

Afghan National Security Forces (ANSF) moved into the area on Friday while coalition troops set up observational posts on high ground over the Yakchal valley.

Over the weekend Afghan troops have moved from compound to compound, meeting little resistance as insurgents attempted to flee.

They uncovered a number of improvised explosive devices (IEDs) as compounds were searched.

Second Lieutenant Chris Trezise, from Maidstone, Kent, of the Princess of Wales Royal Regiment, was among British troops overseeing the operation.

He said the drive was the result of preparatory work to "empower" Afghan forces and "give them the tools to do it for themselves".

Speaking on Saturday, he added: "The objective is to carry out an ANSF clearance operation, with the Afghan National Army clearing north to south and the Afghan National Civil Order Police preventing insurgents fleeing southwards.

"The clearance is going well although it is not yet complete.

"Troops on the ground did not meet much small arms fire but the ANA have found a number of IEDs and suicide vests.

"The Afghan forces are doing very well, we've given them their tasks and they have gone about them very professionally."

The operation comes as coalition troops prepare to withdraw in 2014 and after Afghan president Hamed Khazi called for them to move back to main bases by 2013.

British troops are increasingly moving into mentoring roles, ensuring the Afghan forces are ready to take charge of security.

It is hoped that local security forces will be able to take control of the Gereshk district by the end of this year and this weekend's operation is seen as a vital part of the bid to make the area safe.

A number of suspected insurgents who attempted to flee Yakchal to the south were captured by the Afghan National Civil Order Police (ANCOP) late on Saturday.

They were held for processing by British troops and will be detained by Afghan authorities to await trial.

Officers from ANCOP, approached by locals alarmed by the heavy military presence and the sound of several blasts, offered reassurances and explained the purpose of the mission.