Four Afghan civilians have been killed and one injured in an airstrike called in by British forces, the Ministry of Defence said today.
It is understood two women and two children died in the incident in Helmand Province, southern Afghanistan, yesterday.
A spokeswoman said British troops called in air support after being caught in a Taliban ambush at an undisclosed location in the southern part of the province.
The four bodies and one injured person were found as soldiers went to inspect the area.
The MoD said in a statement: "We can confirm UK forces were involved in an operation in the south of Helmand Province.
"We deeply regret that this incident happened and do everything we can to mitigate this from happening. This incident is currently under investigation and it would be inappropriate for us to comment."
Afghan civilians have repeatedly accused British and US forces of being indiscriminate in their air strikes, with civilians frequently said to be among the victims.
Afghan President Hamid Karzai has voiced his anger and frustration at the number of civilian deaths, which have tended to fuel the local population's resentment of foreign troops.
It was not immediately clear whether British aircraft or those of another force carried out the air strike.
Last month an air strike targeting a Taliban commander killed seven civilians from one family, local Afghan officials said.
A total of 1,977 civilians were killed in fighting in Afghanistan during 2007, including nearly 240 who lost their lives in air strikes by foreign troops, according to a leading Afghan NGO.