(CNN) -- Britain on Saturday demanded the release of Gilad Shalit as the Israeli soldier marked his 24th birthday in Hamas' captivity.
"The thoughts of many in Britain are with Gilad Shalit and his family," the Foreign Office said.
"His detention is unjustifiable and unacceptable. The British Government demands his immediate and unconditional release".
Shalit has been held captive since June 25, 2006, when Palestinian militants from Gaza captured him.
The militants had tunneled into Israel and attacked an Israeli army outpost near the Gaza-Israel-Egypt border, killing two soldiers in the assault.
Israel immediately launched a military incursion into Gaza to rescue Shalit, then 19, but failed to free him.
Since being imprisoned by Hamas, Shalit has not been allowed any contact with the outside world, nor any visits by the Red Cross. Details of his incarceration and physical condition remain unknown.
In October 2009, Hamas released a tape of Shalit as a proof of life, in which he urged the Israeli government to do more for his safe release. CNN
