The Palestinian militant group Lions' Den announced Sunday the extrajudicial killing of a "traitor" in the occupied West Bank.

The group based in the northern city of Nablus said a "traitor" had been "liquidated", in a Telegram post which gave no further details of their identity or activities.

Palestinian public body the Independent Commission for Human Rights also said a man who had been "accused of spying for the Israeli occupation" had been killed on Saturday evening.

A security source in Nablus, who requested anonymity due to sensitivities surrounding the case, told AFP that the man was shot dead in the Old City.

The source identified the person killed as the same man who appeared in a video circulating on social media, which AFP was not able to verify, confessing to spying on the militant group for Israel.

The Lions' Den group said it would "explain to the public... after completing some security measures".

"We direct our message to every traitor who sells his religion, his conscience, his honour and his nation," added the group, which emerged last year.

The Commission said people should not "take the law into their own hands" and warned extrajudicial killings risk sparking "chaos".

It called treason a "heinous crime" that should be punished through the courts.

Israel has occupied the West Bank since the 1967 Six-Day War and its forces have killed multiple Lions' Den militants in recent months.

The Palestinian group has claimed responsibility for numerous attacks targeting Israelis in the West Bank, including the killing of a soldier in October.

So far this year, the Israeli-Palestinian conflict has claimed the lives of at least 92 Palestinians, 18 Israelis, one Ukrainian and one Italian, according to an AFP count based on official sources on both sides. 

These figures include, on the Palestinian side, combatants and civilians, including minors, and on the Israeli side, mostly civilians, including minors, and three members of the Arab minority.