RAMALLAH, West Bank ? As Palestinian street clashes spread Friday from Gaza to Ramallah, Hamas accused loyalists of President Mahmoud Abbas of trying to assassinate Prime Minister Ismail Haniyeh during a chaotic shootout Thursday at a border crossing with Egypt.

The charge raised factional tensions to a boiling point as Abbas prepared to deliver a speech today outlining his next steps to resolve a political deadlock that has triggered spiraling violence and fueled fears of civil war.

With a power struggle between Hamas and Abbas’ Fatah movement unresolved, both sides appeared to be entrenching themselves in positions that suggested little room for compromise.

Hamas, which controls the Palestinian government, accused Fatah of an attempted coup, and Fatah charged that Hamas is fanning the flames of internal strife to cover up its failure in governing the Palestinians.

Talks between the two sides on forming a governing coalition that could help lift international sanctions on the Hamas-led government have collapsed, and Abbas has suggested that he might call new elections, a move that could further inflame the confrontation.

The worsening crisis has also caused concern in Israel, as well as Egypt and Jordan, where radical Muslim groups have challenged the government.

On Friday, Hamas said that Mohammed Dahlan, a Fatah strongman in Gaza, orchestrated an attack by members of Abbas’ presidential guard on Haniyeh’s entourage, which came under fire at the Rafah border crossing after the prime minister crossed into the Gaza Strip late Thursday.

One of Haniyeh’s bodyguards was killed, and his son and a political adviser were wounded.

“This was a cowardly assassination attempt at the hands of a group led by Mohammed Dahlan, who plotted and executed this disgraceful attempt,” Hamas spokesman Ismail Radwan said at a news conference in Gaza. “The filthy hands who attacked this convoy will not go unpunished. We know them very well.”

Khalil al-Hayeh, the head of the Hamas faction in parliament, told mourners at the funeral of Haniyeh’s bodyguard that Dahlan was trying to overthrow the government, and he urged the crowd “to get us the plotters of this coup.”

Dahlan dismissed the accusation, calling it an attempt by Hamas leaders “to mask their sweeping failure to manage Palestinian political and social life.”

Saeb Erekat, a senior aide to Abbas, said at a news conference in Ramallah that Hamas was to blame for the mayhem at the border crossing.

“We hold Hamas fully responsible for the chaos that happened yesterday at the border,” Erekat said.

“As for the threat against my colleague Mohammed Dahlan, Hamas as a movement will bear full responsibility for the consequences of their accusation.”

Haniyeh, surrounded by a phalanx of armed bodyguards, received a tumultuous welcome from tens of thousands of supporters at a rally in a stadium in Gaza City marking the 19th anniversary of the founding of Hamas. In a fiery speech, he said Hamas could not be defeated through assassinations. “We joined the movement to become martyrs, not ministers,” he declared.