The suicide bombers who carried out Monday's attack in Dimona belonged to Hamas and lived in Hebron.
The two, identified as Muhammad Hirbawi and Shadi Zughayar, aged 20, were members of Hamas's armed wing, Izzadin Kassam, the group said in a statement on Tuesday.
Palestinian Authority officials in Ramallah responded by launching a scathing attack on Hamas, accusing the movement of acting against Palestinian national interests. They also accused Hamas of receiving instructions from Iran and Syria to resume suicide attacks against Israel.
"The instructions came from Damascus and the funding from Teheran," a senior PA official told The Jerusalem Post. "They are all determined to undermine the authority of President Mahmoud Abbas and sabotage the peace process."
Another top PA official accused Qatar and Al-Jazeera of openly supporting Hamas in its efforts to discredit Abbas and his Fatah faction. He said the PA had complained about Qatar's "negative" role to several Arab and EU countries.
Al-Jazeera is based in Doha and is owned by a member of the ruling family.
Earlier, Fatah's armed wing, the Aksa Martyrs Brigades, claimed responsibility for the attack and named two young men from the Gaza Strip as the suicide bombers.
Another Fatah-affiliated group in the West Bank also claimed responsibility, naming two other Palestinians as the suicide bombers.
Sources close to Fatah said all four men apparently had been recruited as suicide bombers and dispatched to carry out attacks inside Israel.
The sources said they believed the two men from the Gaza Strip, Musa Arafat and Luai al-Aghwani, had been arrested by the Egyptians after crossing into Egypt with explosive belts.
Fatah has yet to comment on the latest Hamas claim of responsibility. Fatah has also not commented on an explanation for the pictures of the grieving families in the Gaza Strip of the alleged suicide bombers from Fatah.
In its Tuesday statement, Izzadin Kassam said Hamas was planning more attacks in response to the "barbaric and inhumane" blockade of the Gaza Strip.
Abu Obaidah, spokesman for Izzadin Kassam, attributed the delay in announcing his group's responsibility to "security reasons."
He added that Hamas also wanted to confuse Israel by leaving it guessing about the identity of the perpetrators. He also denied reports according to which the suicide bombers had infiltrated Israel from Egyptian territories.
The group said in its statement that the Dimona attack had been aimed at proving to Israel that Hamas was still capable of launching such operations.
The two suicide bombers belong to large Hebron clans that are closely associated with Hamas, and both of them had jobs.
Zughayar was working at a plastic factory and is said to have disappeared a day before the attack. Hirbawi, who worked at a paper factory, is reported to have left Hebron the same day.
Yasser Abed Rabbo, a member of the PLO executive committee and a senior adviser to Abbas, strongly condemned Hamas for carrying out the Dimona attack. He said Hamas was causing grave damage to the interests of the Palestinians by turning itself into a pawn in the hands of Iran and Syria.
