An offshoot of the Middle East's Islamic State insurgency has begun operating on southern Afghanistan, less than three months after British combat troops withdrew from the region.

A man identified as Mullah Abdul Rauf was actively recruiting fighters for the groups, flying black flags and, according to some sources, even battling Taliban militants.

Local sources said Rauf, a former Guantanamo Bay prisoner, had set up his base in Helmand province and was offering good wages to anyone willing to fight for the Islamic State.

Spreading state: Kashmiri protesters hold up a flag of the Islamic State during a demonstration against Israeli killings in Gaza in this July 2014 file photo. There is now an Islamic State group operating in Afghanistan

General Mahmood Khan, the deputy commander of the Afghan army's 215 Corps, said residents of a number of districts in Helmand have said Rauf's representatives are fanning out to recruit people.

'A number of tribal leaders, jihadi commanders and some ulema (religious council members) and other people have contacted me to tell me that Mullah Rauf had contacted them and invited them to join him,' Gen Khan said.

But he said the Taliban, which is active across Helmand, has warned people not to contact Rauf.

PM TO LOBBY OBAMA FOR RELEASE OF LAST GUANTANAMO BRITON David Cameron has promised to lobby Barack Obama for the release of the last British resident held at Guantanamo Bay when he visits Washington this week, the detainee's lawyer said. Shaker Aamer, a Saudi who is married to a Briton, has not been charged with any crime and was cleared for release in 2007 from the U.S. naval base in Cuba. All British nationals and citizens have been released from the detention camp. Obama has pledged to close Guantanamo, opened in 2002 to house suspected militants, but faces obstacles from Congress. According to rights group Amnesty International, Aamer moved to Britain in 1996 and was in Afghanistan doing voluntary work for an Islamic charity when he was captured by Afghan Northern Alliance forces in 2001 and handed to the U.S. military. Aamer's lawyer, Clive Stafford Smith, said Mr Cameron had written to him in the last week to say he would raise the case with Obama. Mr Stafford Smith said that was welcome but not enough. 'He has said this before and little has come of it. Rather than just raising Shaker's case, Mr Cameron must come back from Washington with a concrete date for Shaker's return home to London,' said Stafford Smith, director of the charity Reprieve. Advertisement

'People are saying that he has raised black flags and even has tried to bring down white Taliban flags in some areas,' said Saifullah Sanginwal, a tribal leader in Sangin district, where British troops once patrolled.

'There are reports that 19 or 20 people have been killed' in fighting between the Taliban and the IS group, he added. Sulaiman Shah, who was Sangin district governor until last month, told the Times that Rauf was believed to be moving back and forth to Iraq and Syria via Iran.

'He is telling people that his leader is in Iraq and that they have some activities in some parts of Afghanistan,' Mr Shah said.

Helmand provincial council head Haji Mohammad Karim Atal told the Times that Rauf's Islamic State cell was offering wages of $500 (£330) a month to tempt Taliban fighters to switch sides.

Tensions between the established militant group and the new pretender had reportedly turned deadly on at least one occasion, including a week ago when five or six people were killed when a gunfight broke out between Rauf's followers and those of Mullah Ahmad Shah, the Taliban commander in northern Helmand.

The violence comes less than three months after the withdrawal of British combat troops from the country, where they had been waging war against the Taliban for 13 years.

A total of 453 British forces personnel or MoD civilians died while serving in Afghanistan since the start of operations in October 2001. More than 2,200 members of the U.S. military have died.

Estimates of the number of Taliban fighters killed are sketchy, but range from 25,000 to 40,000. The war also resulted in the deaths of an estimated 18,000 to 20,000 Afghan civilians.

Occupation: The establishment of the Islamic State comes less than three months after the withdrawal of British combat troops from Afghanistan, where they had been waging war against the Taliban for 13 years

Rauf was a corps commander during the Taliban's 1996-2001 rule of Afghanistan, according to Amir Mohammad Akundzada, governor of Nimroz province, who says he is related to Rauf but has not seen him for almost 20 years.

Both Gen Khan and Amir Akunzada said Rauf was apprehended after the fall of the Taliban in the U.S.-led invasion of Afghanistan and was detained for years at Guantanamo Bay.

They suggested Rauf may have fallen out with Taliban leaders after spending time in the Pakistani city of Quetta, where Afghan officials and analysts believe senior Taliban leaders are based.

People who want to fight in Afghanistan just create new names - one day they are wearing white clothes (of the Taliban) and the next day they have black clothes and call themselves Da'esh, but they are the same people

A video released on Saturday purports to show militants from both Afghanistan and Pakistan pledging support to Islamic State. But Amir Akundzada said the group was not likely to gain traction with ordinary Afghans.

'People who want to fight in Afghanistan just create new names - one day they are wearing white clothes (of the Taliban) and the next day they have black clothes and call themselves Da'esh, but they are the same people,' he said, using the Arabic acronym for the Islamic State.

In Washington, State Department spokeswoman Marie Harf said the U.S. has noted the 'rhetorical message of support' for Islamic State by some in Afghanistan.

'We continue to watch for signs that these statements could amount to something more than just rhetorical support,' she said. 'That doesn't mean it's unimportant.'

Analysts say most claims of allegiance to IS in Afghanistan have been motivated by opportunism and that a new jihadist outfit would find it difficult to establish a presence where there are already long-established militant groups with tribal links.