One soldier from 21 Engineer Regiment was killed in a blast and another in a traffic accident, the Ministry of Defence said. Next of kin have been informed.
The soldier who died on Sunday in a blast in Sangin, Helmand Province, was named as Cpl Harvey Alex Holmes, 22, from Hyde, Greater Manchester.
The deaths, both in the Nad-e Ali area of Helmand, took the number of British service personnel who have died since the start of operations in Afghanistan in 2001 to 284.
Spokesman for Task Force Helmand, Lt Colonel James Carr-Smith, said of the soldier killed in the blast: "He was travelling to meet up with local Afghan contractors prior to continuing with reconstruction programmes when he was killed in an explosion.
"He died seeking to improve the lives of the people of Helmand Province. His sacrifice will not be forgotten."
Lt Col Carr-Smith said of the soldier killed in the traffic accident: "He was part of a team conducting a reconnaissance to replace a bridge over a canal in the Nad-e Ali District of Helmand, in order that local Afghans could travel more freely, when he was killed in a traffic accident.
"He died in the course of his duty; we will remember him."
The MoD said that Cpl Holmes, of 1st Battalion The Mercian Regiment, was providing protection for his patrol as it investigated a compound when yesterday's fatal explosion happened.
He was killed by an improvised explosive device (IED) close to patrol base Waterloo, in Sangin.
His family released a statement which read: "Harvey lived for his family and his friends but his passion was the Army.
"He has made his family extremely proud for the sacrifice he has made and will be missed every day. Harvey has died a true hero and will be with us forever in our hearts."
His death was the first since April 7.
Lt Col Andrew Hadfield, Commanding Officer 1st Battalion The Mercian Regiment (Cheshire), said: "He showed true promise and had a great future, but this has been cruelly stolen from him, his family, his girlfriend and his many friends.
"In his five years with the First Battalion he had passed some of the most arduous courses on offer, and served in Northern Ireland, Belize, the Falkland Islands and Iraq. He had been promoted twice in quick succession, most recently to corporal just last Christmas."
He added: "We will remember him as the Cheshire oak that he was, standing firm always, and striking hard only to save others who were in trouble.
"He was the epitome of the modern British soldier and we will miss him deeply. Our thoughts are with his family and friends at this most difficult of times."
Major Mark Ellwood MBE, Officer Commanding A Company, 1st Battalion The Mercian Regiment (Cheshire), added: "Corporal Harvey Holmes, known by all as 'Holmesy', was the very epitome of professionalism.
"Whilst serving in the Falkland Islands, he was able to visit Mount Longdon where his late father had served with the Parachute Regiment during the 1982 conflict.
"This was an emotional experience for him as his father was a huge inspiration to him."
Defence Secretary Bob Ainsworth said: "I was so very sorry to hear of the death of Corporal Holmes.
"He was clearly a hugely popular and capable soldier whose talents had been recognised through quick promotion within 1st Battalion The Mercian Regiment.
"That he died providing protection for his comrades speaks volumes of his bravery.
"My thoughts are with his fiancee, his family and friends at this difficult time."