Last updated at 00:08 04 June 2007

Prince Harry's hopes of seeing active service as an Army officer in Afghanistan are in doubt amid mounting concern over casualty levels among British troops.

In addition to two deaths in the last week, Army sources have revealed that a single infantry battalion recently saw around a dozen of its soldiers airlifted back to Britain suffering critical injuries within a three-week period.

In addition, other soldiers suffered less serious battlefield wounds treated at field hospitals.

Insiders say the intensity of fighting against the Taliban has risen markedly in recent weeks, as Nato forces try to drive the insurgents out of key areas across Helmand Province where most UK forces are located.

The head of the Army General Sir Richard Dannatt announced last month that he was cancelling Prince Harry's planned deployment to southern Iraq at the last minute, due to fears that his presence would attract more attacks from insurgents and put his fellow-soldiers in greater danger.

The Mail revealed alternative plans for the 22-year-old prince to be sent on a low-profile trip to Afghanistan later in the summer, to carry out relatively safe tasks such as training the Afghan security forces.

But the level of violence in Helmand Province raises questions over whether the Prince would be any safer in Afghanistan than he would be in Iraq.

According to insiders around a dozen soldiers from the 1st Battalion the Royal Anglian Regiment had to be evacuated to Britain by air in the first three weeks of May after suffering severe injuries.

Several had lost limbs, while others were critically injured by shrapnel from roadside bombs or rocket-propelled grenades.

The gruelling casualty rate comes amid intensive fighting in several areas, including the southern frontier town of Garmsir which controls a key Taliban supply route from neighbouring Pakistan, and the area around the strategically vital Kajaki hydroelectric dam in the north of the province where Nato forces launched a fresh offensive last week.

Five Britons have been killed in the last month and a total of 31 casualties were flown home to Britain in the first two weeks of May - matching the figure for the whole of April.

The most recent British fatalities were Corporal Darren Bonner, aged, 31, of the 1st Battalion The Royal Anglian Regiment who was killed by a roadside bomb last Monday, and Corporal Mike Gilyeat, 28, of the Royal Military Police who was among seven men who died when a U.S. Chinook helicopter crashed near Kajaki on Wednesday.

Ominously, officials have admitted the Chinook may have been shot down by Taliban fighters - the first such loss in Helmand.

Chinooks are in constant use to shuttle British troops and supplies around the sprawling province and a successful attack from the enemy on the ground would be a disturbing development.

Last month British officers serving in Afghanistan admitted they were fighting an "undeclared war" against Iranian-backed militias, equipped with increasingly sophisticated and effective weaponry and tactical skills.

Although UK forces have defeated the Taliban in every battle and skirmish to date, at times they have come perilously close to disaster, commanders admit.

British and Nato forces have the huge advantage of air power but they lack the manpower needed to hold wide areas of territory for long periods, meaning that the Taliban often return to areas when UK troops withdraw, and often the same ground has been fought over many times.

Prince Harry, a cornet or 2nd Lieutenant in the Blues and Royals Regiment, had originally hoped to spend six months leading a 12-strong armoured reconnaissance patrol in the deserts of Iraq.

But intelligence reports of planned attempts to assassinate or kidnap him forced senior defence chiefs to cancel his deployment at the last minute, and his men are now being led by a stand-in officer.

A final decision over whether he can serve in Afghanistan will not be taken for some weeks, according to insiders.

Despite the fierce fighting in Helmand a range of options remain open, including sending Harry to work at the Nato headquarters in the capital Kabul, which remains relatively safe.

He could also be given a role at the Camp Bastion, the main British base in Helmand which is located in remote desert, and has so far not come under direct attack.