British troops are facing criminal investigations over the killing of 52 Afghans during Britain's military campaign in the country.

According to British newspaper, The Telegraph, ministers fear lawyers are about to bring a new wave of cases against troops following a barrage of legal action seen after the Iraq war.

This comes just days after Britain's Chief of General Staff said such civil action could "undermine" Britain's ability to fight future conflicts.

The newspaper reports that the U.K's ministry of defense has set up an investigative unit called Operation Northmoor to deal with the Afghan claims.

The unit is made up of 64 Royal Military Police officers who are investigating 166 separate cases, which include 52 deaths from 15 different incidents.

The law firm Leigh Day, which has been criticized by ministers for bringing "spurious" cases from the Iraq war, is representing 81 of the Afghan claimants.

The firm has denied any wrongdoing from its work in Iraq and says the Government is trying to place the Armed Forces above the law.

However, The Telegraph reports that David Cameron has vowed to crack down on what he calls "an industry trying to profit from spurious claims that are lodged against our brave servicemen and women".

The Iraq Historic Abuse Team set up by the MoD has already spent five years investigating a tiny fraction of more than 1,500 allegations of abuse and killing during the Iraq campaign made by Leigh Day and another firm, Public Interest Lawyers. In that time, the only punishment handed down so far has been a £3,000 fine. The £57 million investigation being carried out by 145 staff is due to last until the end of the decade.

Defense sources said ministers and commanders fear the aftermath of the Afghan campaign will now become bogged down in similar legal challenges, but ministers say they have no choice. Troops could find themselves on trial in The Hague if Britain is seen to be failing to conduct a thorough investigation of alleged abuses.

The newspaper reports that the alleged Afghanistan abuses date from 2011 to 2013 when the British presence in Helmand was at its peak.

But according to them, Operation Northmoor officers have finished investigating three of the alleged incidents of unlawful killing, representing six alleged deaths, and no charges have been brought.

Johnny Mercer MP, a former army officer who served in Helmand province, said: "It's going to go on for ages, it's going to cost loads of money and no one will go to prison."

He said: "There's not another nation on earth that puts its soldiers through this and I find it hard to understand."

A MoD spokesman was quoted by The Telegraph as saying: "There is a legal requirement to investigate credible allegations of criminal offences by UK Forces, which are held to the highest standards wherever in the world they may be. By no means all allegations lead to police investigations and no one is prosecuted on the basis of allegations alone.

"But we are determined to reduce significantly the number of spurious claims brought against our troops.

"Every false, distorted or exaggerated claim diverts defense spending from the front line and could serve to constrain the Armed Forces in their operational effectiveness."