JERUSALEM — The Palestinian Authority president, Mahmoud Abbas, yesterday described the Hamas militant group now controlling Gaza as “murderous terrorists” intent on creating an “empire of darkness and injustice.”

“There is no dialogue to be initiated with those murderers,” Mr. Abbas said in his first public addressed since Hamas gunmen seized control of the Gaza Strip last week. His uncharacteristically fiery speech raised concerns that the confrontation between the Islamist group Hamas and Mr. Abbas’s more moderate Fatah Party could escalate.

Mr. Abbas said the separation of Gaza from the West Bank was a threat to hopes for a Palestinian state, and accused Gaza militias of taking money “from many parties in many directions” for their “malicious desire to establish an empire of darkness and injustice.”

“It’s a fight between the national project and this small kingdom they want to establish in Gaza, the kingdom of Gaza, between those who are using assassination and killing to achieve their goals, and those who are using the rules of law,” he said.

The Palestinian Arab leader demanded concessions from Israel for greater freedom of movement in the West Bank — the larger, inland Palestinian territory — and called for discussion on an international force to maintain order in Gaza.