As the IDF offensive concluded its fourth day on Tuesday, Hamas accused the Palestinian Authority of planning to return to the Gaza Strip with the help of Israel.

According to a report published by the Hamas-affiliated Palestine Information Center Web site, PA President Mahmoud Abbas has ordered his officials in Ramallah to set up an "emergency room" to prepare for reassuming control over the Gaza Strip after the Hamas government is toppled by Israel.

It said the emergency room consisted of commanders of the PA security forces and the interior minister.

The report claimed that Abbas was coordinating his moves with the Egyptians and the Saudis.

It also quoted sources in Ramallah as saying that Abbas's top adviser, Nimmer Hammad, phoned Defense Ministry official Amos Gilad last week and told him that the PA "believes in Israel's right to liquidate Hamas."

Earlier this week, two senior PA officials told The Jerusalem Post that the PA was "ready" to return to the Gaza Strip when and if the Hamas government was overthrown.

The Hamas allegation, which has been strongly denied by the PA, is an indication of the growing tensions between the Islamist movement and Abbas's Fatah faction in the wake of the IDF offensive.

Tensions between the two parties peaked earlier this week when Abbas and other PA leaders held Hamas responsible for the current violence because of its refusal to extend the cease-fire with Israel.

Hamas officials are convinced that one of the main goals of the IDF operation is to remove the Hamas government from power so as to pave the way for the return of Abbas's men to the Gaza Strip.

Hamas legislator and spokesman Mushir al-Masri claimed that Abbas had known in advance about the exact timing of the "surprise" IDF attack.

"It's no secret that Abbas knew in advance about the attack," he said. "This is not our analysis; rather, it's based on information we received recently."

A Hamas official in Gaza City also claimed that former Fatah security commanders who fled the Strip during the Hamas takeover in the summer of 2007 were holding meetings in Cairo and Ramallah to discuss returning home.

"These Fatah members are working with the Egyptians, Israelis and Americans," he said. "They include [former Fatah security chiefs] Muhammad Dahlan and Rashid Abu Shabak."

The Hamas official accused the Fatah representatives of providing Israel with "vital information" about the location of Hamas security installations.

A leaflet distributed by a Fatah group in Gaza urged supporters of the faction to prepare for the possibility of taking control over the Gaza Strip.

The leaflet said that the Palestinians in the Strip were being held "hostage" by Hamas, which has humiliated and starved them.

It called on all Hamas members in Gaza who were not involved in crimes against Fatah and the Palestinian people to seek refuge with the heads of major clans to avoid being punished.

Fatah also called on all its members and supporters to be prepared to assume full control over the Gaza Strip "to impose law and order and defend the Palestinian people."

However, a Fatah official in Ramallah denied that his faction was behind the leaflet, saying he did not rule out the possibility that it was part of Hamas's "fabrications."

The official said he was unaware of any plans by the PA to return to the Gaza Strip.

"We want to see an end to the brutal Hamas regime, but that should be done by the Palestinians and not Israel," he said. "Hamas is so desperate that they have begun spreading lies and inciting against the PA and Egypt."