A short-lived "honeymoon" between Fatah and Hamas ended abruptly Saturday when the Islamist movement accused Palestinian Authority President Mahmoud Abbas's office of being behind an attempt to assassinate Hamas Prime Minister Ismail Haniyeh. The charges came just as Fatah and Hamas appeared to be close to launching negotiations over solving their dispute. Relations between the two parties warmed up after Abbas phoned Hamas leader Mahmoud Zahar last week to offer his condolences over the death of his son. This was the first time high-level contact between representatives of the two parties since Hamas took full control over the Gaza Strip last June. The phone conversation raised hopes among many Palestinians that it would pave the way for reconciliation between Hamas and Fatah. The hopes grew when a senior Fatah delegation headed by Ibrahim Abu al-Naja, a top Fatah operative, visited Zahar to offer its condolences over the death of his son. The ongoing Israeli military operations in the Gaza Strip prompted Hamas and Fatah leaders to call for ending the power struggle between the two sides. And for the first time in seven months, Hamas and Fatah officials appeared together on several TV stations to call for "national unity." But Hamas dropped a bombshell Saturday when it openly accused Abbas's office of planning to kill Haniyeh. Said Siam, a senior Hamas official, claimed that Abbas's men also planned to bomb Hamas's Al-Aksa TV station. According to Siam, one of Abbas's top aides, Tayeb Abdel Rahim, had personally dispatched a suicide bomber who was supposed to blow himself up during Friday prayers in Gaza City attended by Haniyeh. Abdel Rahim reportedly promised the would-be-suicide bomber, who was arrested by Hamas security forces at the scene, that the PA would move his family to Ramallah if the operation succeeded. He also promised that the PA would rebuild his family's house if Hamas destroyed it. The Hamas official said the would-be-suicide bomber had even prepared a videotape talking about his mission that was supposed to be broadcast on the PA's Palestine TV after the attacks on Haniyeh. He added that other suicide bombers belonging to Abbas's Fatah party were supposed to carry out an attack on Al-Aksa TV in Gaza City. Siam also named three Fatah operatives, Ahmed Dughmush, Hassan Zant and Dafer Abu Mazkour, who had fled to Egypt after the Hamas takeover of the Gaza Strip, as being directly responsible for the botched assassination attempt. He said Hamas had briefed the Egyptian government about their involvement in the alleged plot and had demanded that they be brought to trial. Siam, who served as Interior Minister in the Hamas government, also said that Hamas had briefed a number of Arab and Islamic countries about the details of the assassination scheme. He said several Fatah operatives living in the Gaza Strip have disappeared from their homes for fear of being arrested because of their involvement in the attempt to kill Haniyeh. He said that the Fatah suspects were planning to issue a statement on behalf of al-Qaida and Fatah al-Islam claiming responsibility for the assassination. In response to the allegations, a senior official in Abbas's office told The Jerusalem Post that Hamas was lying "to cover up for its crimes" against the Palestinians in the Gaza Strip. "This is a new fabrication by Hamas," he said. "They want to divert attention from the state of anarchy and lawlessness and the crimes of their murderous gangs." Ahmed Abdel Rahman, a top aide to Abbas, denied the Hamas charges, saying they were reflected the "sick mentality" of the Hamas leaders. "This is the time for national unity," he said. "Hamas does not want unity because they want to retain control over the Gaza Strip." Fatah's armed wing, the Aksa Martyrs Brigades, accused Hamas of seeking to deepen divisions among the Palestinians by accusing the PA leadership of trying to kill Haniyeh. "Fatah had nothing to do with this case," the group said. It called for putting Siam on trial for his part in killing some 400 Palestinians over the past seven months.