A British soldier who went missing in southern Afghanistan Monday has been found dead.

Britain's Defense Ministry said the soldier was found shot dead following an extensive search, but added that the exact cause of death was unknown.

Officials say the soldier was based in Helmand province and went missing early Monday morning.

Earlier, a Taliban spokesman claimed that its fighters kidnapped and killed the British soldier after a firefight in Helmand. However, the group is known to regularly exaggerate its claims.

News of the kidnapping came as British Prime Minister David Cameron made a surprise visit to Afghanistan.

Mr. Cameron arrived at Camp Bastion in southern Helmand province Monday, but later cancelled plans to visit a base in Lashkar Gah so that helicopters could be used in the search.

Britain has about 9,500 troops in Afghanistan, the second-largest foreign contingent in the country. Most of the British soldiers are in Helmand province, one of the most violent areas of the country. Mr. Cameron is expected to soon announce a drawdown of forces in the country.

Meanwhile Monday, NATO says a soldier was killed by a bomb blast in eastern Afghanistan.

Presently, just one NATO soldier is believed to be in captivity. Bowe Bergdahl, a 25-year old US soldier, who disappeared from his base in Paktika province in eastern Afghanistan in June 2009.