Aljazeera satellite channel received a statement issued by the Jihad Jibril Brigades, saying they had carried out "an operation late Friday against an enemy vehicle".
It said the attack was mounted by two of its members as part of the PFLP-GC's continued armed struggle against Israel.
Israeli army radio said the two victims were a settler couple.
Their car was hit with automatic weapons fire before the assailants approached and killed the couple at point-blank range, it said.
The attack took place just inside the Green Line separating Israel from the West Bank, at the level of Eshkolot settlement, about 20km southwest of the Palestinian town of Al-Khalil (Hebron).
The PFLP-GP (General Command) is led by Ahmad Jibril, a Palestinian who served as an officer in the Syrian army. His son, Jihad, was killed in a 2002 car bombing in Beirut that the Palestinians blamed on Israel.
Meanwhile, an explosion inside a house has critically injured a Hamas member and his wife on Saturday, Palestinian security officials said.
Police were investigating the cause of the blast, which reportedly appeared to be the result the accidental detonation of bomb-making material.
Hospital officials identified the wounded man as Yusuf Shahan, 29, a Hamas member.
His wife was also wounded in the blast, but the extent of her injuries was not immediately known.
Also in Gaza Israeli occupation forces destroyed 84 shops in the northern Gaza Strip town of Bait Hanun on Friday.
The destroyed shops provided
employment to several families
According to investigations conducted by the Palestinian Centre for Human Rights (PCHR), Israeli forces raided Palestinian shops on both sides of the road on route to the Palestinian side of the Eretz crossing.
The raid began early afternoon with soldiers breaking down the entrances to shops and raiding the buildings.
By late evening, the Israeli forces had destroyed 84 shops which employed 250 people, providing income to dozens of Palestinian families.
"These shops were selling foodstuffs and were built in 1995 to serve Palestinian workers on their way to workplaces in Israel", said the PCHR in a statement.
The PCHR is concerned "this destruction may be part of a wider Israeli plan to destroy the remaining commercial facilities in the area for the purpose of expanding the buffer zone near Eretz crossing, in complete disregard for the large losses which would be incurred by Palestinian civilians".
Since the beginning of the present Intifada until the end of 2003, Israeli occupation forces have destroyed 333 Palestinian economic facilities, according to the PCHR.