The British soldier, from the 2nd Battalion Royal Welsh, died Sunday in an explosion while on patrol in northern Helmand Province, the British Ministry of Defense said.
Three soldiers died Saturday in a non-combat accident, while two other soldiers were killed in two separate accidents Saturday, NATO's International Security Assistance Force said.
In Herat City, a suicide bomb Sunday killed four civilians in an attack targeting Energy Minister Ismail Khan, who was unharmed, CNN reported.
The suicide car bomber targeted Khan's convoy, which was en route to the airport in Herat City in western Afghanistan, government spokesman Naqib Arween told CNN.
Five members of Khan's convoy were among 20 people suffering injuries in the attack, Arween said.