Palestinian president Mahmoud Abbas on Monday directly accused hamas of carrying out a bomb attack against Prime Minister Rami Hamdallah in Gaza last week and threatened fresh sanctions against the group.
Mr Abbas had previously said Hamas was responsible as it controls security in the Palestinian enclave, but Monday evening said it was "behind the attack".
Mr Hamdallah was uninjured in the March 13 attack, when a roadside bomb exploded as his convoy entered Gaza in what Palestinian officials have called an assassination attempt.
Six of his security guards were lightly hurt.
Speaking to Palestinian leaders in the West Bank city of Ramallah, Mr Abbas said if the attack had succeeded it would have "opened the way for a bloody civil war."
He said the incident would "not be allowed to pass" and announced he would take unspecified "national, legal and financial measures".
Hamas did not immediately respond to the comments.
The Islamist group and Mr Abbas's secular party Fatah have been at odds since 2007 when Hamas seized control of Gaza in a near civil war.
Mr Abbas controls the internationally recognised Palestinian government, based in the occupied West Bank.
He has previously taken a series of measures, including reducing electricity payments for Gaza, where two million people live, in what analysts said was an attempt to punish Hamas.
Hamas and Fatah agreed on a reconciliation agreement in October but it has collapsed.