A video has emerged showing an IDF soldier shooting an injured Palestinian alleged to have carried out a knife attack in the head at a checkpoint in the West Bank.

The footage captured and distributed by Israeli human rights group B'Tselem shows the aftermath of an attack in Tel Rumeida district of Hebron in which an Israeli soldier was wounded by two Palestinian men.

In the footage, one of the alleged attackers lies injured on the ground while the wounded Israeli is helped into an ambulance. An IDF soldier then appears to execute the Palestinian man at point blank range. Shortly after blood runs from a wound in the Palestinian's head.

The Palestinian in the footage has been identified by the Guardian as Abdel-Fattah al-Sharif, 21. A second Palestinian, Ramzi al-Qasrawi, 20, was also shot dead in the attack.

"It is clear that the Palestinian youth who was one of the two who stabbed the soldier was lying on the ground without posing any risk to security services," Sarit Michaeli, a spokeswoman for B'Tselem told AFP. "The security personnel around him are not treating him in any way like he is a danger. The soldier is simply seen shooting him in the head."

The IDF said that the unit's commander had reported the incident, and the soldier had been arrested. "The Israel Defense Forces views this incident as a grave breach of IDF values, conduct and standards of military operations," IDF spokesman Lieutenant-Colonel Peter Lerner told Reuters. "A military police investigation has commenced and the soldier involved has been detained."

An Israeli hospital spokesman said that the injured soldier was receiving treatment, and that his condition was not serious.

Israel's defence minister Moshe Ya'alon described the soldier's actions as being "in utter breach of IDF values and of our code of ethics in combat." He added: "Even when the blood boils, we must not allow such loss of reason and such loss of control."

Ayman Odeh, leader of a bloc of Arab parties in the Israeli parliament also condemned the killing: "Israel has turned in recent months into a place in which executions are carried out in public with the encouragement of cheering mobs."

Human rights groups have previously accused Israeli security forces of extrajudicial killing of Palestinians. In the last six months 28 Israelis and two Americans have been killed in a wave attacks by Palestinians. Over the same period, 188 Palestinians have been killed by Israeli security services.