Britain contributes about 9,500 soldiers to the international coalition in Afghanistan [GALLO/GETTY]

Two British soldiers have been arrested and questioned over allegations of "inappropriate behaviour" in Afghanistan, the UK's Ministry of Defence announced after a newspaper described their alleged abuse of two 10-year-old boys.

Quoting defence sources, The Sun newspaper reported on Wednesday that a sergeant and a private from the Mercian Battle Group had recorded their abuse of the children on video and showed it to other soldiers on laptops.

Military police launched an investigation into allegations against the two soldiers, a ministry spokesperson said, but declined to comment on the nature of the allegations.

"Two service personnel have been arrested, interviewed under caution and released," the spokesperson said, adding that the ministry took any such allegations extremely seriously.

Afghan President Hamid Karzai's office responded in a written statement, saying that the government in Kabul was "deeply disturbed" by the reports and that the alleged behaviour was "immoral".

"The government of Afghanistan is immensely disgusted by the rise in recent incidents of immoral nature among foreign soldiers that clearly undermine public confidence and the Afghan people's co-operation with foreign troops," Karzai's office said.

The statement said the government was "deeply disturbed by reports that two British soldiers have encouraged two Afghan children to touch them through their clothes".

'Moral standards'

A spokesperson for the NATO-led coalition in Afghanistan said they were aware of the allegations.

"We expect members of all ISAF troop-contributing nations to adhere to the highest standards of military service,"
Brigadier General Carsten Jacobson, spokesperson for the NATO-led International Security Assistance Force, said.

"An investigation has been launched, and if a service member is found to have committed an offence, or behaved in a manner not in keeping with the appropriate moral standards expected of them, they will be dealt with appropriately through the respective nation's military judicial system."

The arrests come just a week after a video emerged showing US Marines urinating on corpses, believed to be dead Taliban fighters, in Afghanistan.

The tape of the Marines also prompted reference to earlier scandals involving US soldiers' treatment of prisoners in Iraq and the killing of unarmed civilians in Afghanistan.

The US military has been prosecuting soldiers from the Army's 5th Stryker Brigade on charges of murdering unarmed Afghan civilians while deployed in Kandahar province in 2010.

Britain has about 9,500 troops in Afghanistan, mainly based in the country's Helmand province. Britain says that it intends to pull out all its combat troops by 2015.