Nato said the transition of power to Afghan forces would upset the Taliban British troops in Afghanistan's volatile Helmand province have handed control of the city of Lashkar Gah to Afghan security forces.
In recent days Nato handed over the relatively peaceful province of Bamiyan and the eastern town of Mehtar Lam.But correspondents say that maintaining stability in Lashkar Gah will be the sternest test yet for local forces.
The handover is seen as a critical step in a transition of power before foreign troops end combat operations in 2014.
A handover ceremony took place at the governor's palace in Lashkar Gah.
Afghan Minister of Defence Gen Abdul Rahim Wardak carried out an inspection of Afghan forces, before a handshake between the provincial Governor Mangal and the Isaf commander of south-west Afghanistan, General Toolan.
The new commander of Isaf forces in Afghanistan, Gen John Allen, was also present.
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Lashkar Gah
- Capital of Afghanistan's volatile Helmand province
- Historically called Bost, the city was first founded about 1,000 years ago
- The modern city was built in the 1950s as a base for US engineers working on an irrigation project
- The population of Lashkar Gah is 35,900 according to a 2006 central statistics figures
The handover ended with UK forces leading a procession of their military vehicles as Afghan officials gave them flowers.
The BBC's Jonathan Beale, who attended the ceremony, says it marked the beginning of the end for British control of the area, and that a genuine transfer of responsibility for security is taking place.But British forces are only transferring responsibility for central Lashkar Gah, our correspondent says. They are still looking after certain parts of the city and will be on hand to assist Afghan security forces.
A lot of Afghan people are sceptical of whether their government is ready to take responsibility, he adds.
There is some confidence in the army and police but about 20% of police officers are "ghosts" - there on paper but with money going into someone else's pocket, our correspondent says.
Afghan Foreign Ministry spokesman Janan Mosazai told the BBC that the handover in Lashkar Gah was about more than just the transfer of security responsibilities.
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The reality is that British troops will remain at their base in Lashkar Gah in a support and training role. They're also still leading the fight - along with American troops - in most of Helmand.
But the transfer of responsibility does mark an important step for Nato. It signals that as they prepare to draw down their own forces, they're getting ready to hand over the war to Afghans themselves.
The question now is whether the Afghans are up to the job? Much work has been done on training Afghan security forces, but corruption - particularly within the Afghan national police - remains a problem.
This first wave of transition has been described by one Nato official as a "soft opening". The more highly contested regions of Afghanistan - where the insurgency is still strong - will take longer to transition.
Analysis
The Afghans put on a carefully choreographed ceremony at the heavily guarded governor's palace in Lashkar Gah. A sign that they see the transfer of security of the capital of Helmand as an important occasion, even if British officials have downplayed its significance.The reality is that British troops will remain at their base in Lashkar Gah in a support and training role. They're also still leading the fight - along with American troops - in most of Helmand.
But the transfer of responsibility does mark an important step for Nato. It signals that as they prepare to draw down their own forces, they're getting ready to hand over the war to Afghans themselves.
The question now is whether the Afghans are up to the job? Much work has been done on training Afghan security forces, but corruption - particularly within the Afghan national police - remains a problem.
This first wave of transition has been described by one Nato official as a "soft opening". The more highly contested regions of Afghanistan - where the insurgency is still strong - will take longer to transition.
"The whole purpose of this transition process is to ensure, in the long term, that we have a stable, secure, peaceful Afghanistan because that is in the interest of security and stability in the broader region and the wider world," he said.
"The flipside of that, of course, is that an insecure and unstable Afghanistan is a threat to international security and stability, as was clearly demonstrated by 9/11 and 7/7 in the UK."Nato Secretary-General Anders Fogh Rasmussen told the BBC that the transition of power would upset the Taliban, who have been responsible for a series of high-profile attacks in recent weeks.
"Transition means that the Taliban will be attacking their own countrymen in the future because Afghan security forces will do the combat and of course the Taliban doesn't like that.
"This is the reason why they now try to test the transition but we will stick to the timetable we outlined in November last year."
On Monday, seven policemen were killed at a checkpoint near Lashkar Gah and on Saturday a British soldier was killed while on a routine patrol in the area - some reports suggest he was shot by a man in an Afghan army uniform.
Recent violence
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The Afghan police have a crucial role in the strategy but there are serious concerns about corruption
Hours after the first handover ceremony in Bamiyan, militants killed a key presidential aide in a raid on his Kabul home.
On Tuesday, there were reports of a mortar attack near the capital of eastern Laghman province, Mehter Lam, as Nato was handing over responsibility for that city.
The remaining four areas to be handed over are:
- Kabul province
- Panjshir province
- Herat city
- Mazar-e Sharif city
There have also been a number of high-profile attacks including an assault on a luxury hotel in Kabul that left 22 people dead.
There are currently about 140,000 foreign troops in Afghanistan - nearly 100,000 of them from the US - still battling the Taliban insurgency.
After their withdrawal, the primary role of foreign troops will be to train and equip Afghan security forces.
The approximately 10,000 British troops serving under Nato command are set to complete their withdrawal from Afghanistan by the end of 2014.
Are you in Lashkar Gah, or elsewhere in Afghanistan? What is your reaction to the handover? You can send us your views and experiences using the form below.
