Image caption British soldiers undergo training on the rules of engagement, the MoD said

A British soldier has been jailed for stabbing a 10-year-old boy while serving in Afghanistan, the Ministry of Defence has confirmed.

Grenadier Guardsman Daniel Crook was jailed for 18 months and dismissed from the Army in June for stabbing Ghulam Nabi in Helmand Province.

It has now been revealed that a court martial heard how Crook stabbed the boy in the kidney area with a bayonet.

He had been drinking heavily the night before the incident in March last year.

The court martial hearing was told that he had drunk a "considerable quantity of vodka", and had been treated by medics.

Confiscated rifle

The next day his unit left a checkpoint in the Nad e Ali district to go on patrol.

Crook followed, arming himself with two grenades and a bayonet because his rifle had been confiscated as a safety measure.

The prosecution said he came across two Afghans riding bikes - one of them was Ghulam, who had been sent out to collect a bottle of yoghurt and who then pestered Crook for chocolate.

In response, the soldier "took hold of the boy's shoulder and stabbed him in the region of his kidneys with his bayonet".

Afterwards, Crook caught up with the patrol and admitted what he had done. When questioned by military police he could not explain why he stabbed the boy.

'Still suffering'

The boy's father Haji Shah Zada, 72, told the Guardian newspaper that he could not understand why his son was attacked and had received no apology from the British forces.

The shopkeeper and farmer said his son was still suffering and has not yet been back to school.

He said British forces were "in Afghanistan to build the country and remove insurgents, not to stab a child".

Britain's military police have investigated 99 incidents in which UK forces had been accused of killing or wounding Afghan civilians between January 2005 and March this year, according to the newspaper.

An MoD spokesman said: "Protecting the Afghan civilian population is one of ISAF and the UK's top priorities.

"All British troops undergo comprehensive training on the strict rules of engagement that UK forces and ISAF operate under. Any allegations of infringements of these rules of engagement are investigated thoroughly.

"Those who are found to fall short of the Army's high standards or who are found to have committed an offence are dealt with administratively - up to and including discharge - or through the discipline process, as appropriate."