The killing of three British soldiers in Helmand Province has taken the UK's death toll from operations in Afghanistan, which began in October 2001, to 444. Six have died this year.
The latest deadly attack came on the third day of the Taliban's self-proclaimed "spring offensive".
The soldiers, from The Royal Highland Fusiliers, 2nd Battalion The Royal Regiment of Scotland, were on routine patrol in Nahr-e Saraj district when their vehicle was hit by an improvised explosive device.
They received immediate medical attention and were evacuated by air to the Military Hospital at Camp Bastion but could not be saved, the MoD said.
Other blasts throughout the country killed nine civilians and a police commander.