One UK soldier has been killed and two seriously injured after a battle with the Taleban in southern Afghanistan, the Ministry of Defence has said.
British troops are stationed in the southern province of Helmand
The death is believed to be the first fatality since British troops deployed to the volatile area of Helmand province in recent months.
It came after a US soldier was killed in a bomb blast in eastern Afghanistan.
About 3,300 British troops are based in Helmand as part of the Nato-led peacekeeping force.
A Ministry of Defence spokeswoman said: "It is with great regret that I can confirm that UK forces have suffered a fatality as a result of an incident in the Helmand province of Afghanistan."
She said "a mobile patrol was engaged in a firefight against suspected Taleban forces" which resulted in the death and serious injuries.
The incident took place in Sangeen, a small town taken from Taleban control earlier this year by Afghan security forces backed by US air power.
Afghan sources said several Taleban soldiers were killed in the fighting.
British Apache helicopter gunships were called in to support the troops.
Defence Secretary Des Browne offered his condolences to the families of those involved in the incident and to "those troops continuing their difficult task of helping to ensure Afghanistan remains secure".
The Army's deployment to Helmand, led by 16 Air Assault Brigade, began earlier this year and was expected to be completed by June.
In the east of the country, a coalition spokesman said a bomb hit a US armoured vehicle in a village in Ghazni province after a shoot-out with suspected Taleban fighters.
Elsewhere in Ghazni, gunmen shot dead three people on Saturday night, officials said. In Kandahar province four road workers were also killed.