A series of rallies on Friday in Gaza marking Hamas' founding came days after efforts to work out a ceasefire among Palestinian resistance groups collapsed.
"Bodies of Qassam men (Hamas human bombers) will continue to blow up in the depth of the Zionist entity," the group's top official, Abd al-Aziz al-Rantissi, told a cheering crowd in Gaza's Jabalya refugee camp.
"We will not allow any of those burnouts to sell out Palestine," Rantissi said, referring to the diplomatic moves for peace in the region.
Rantissi also railed against the "Geneva Accord", a symbolic peace initiative calling for most Jewish settlements in the West Bank and Gaza to be dismantled and for Israel to have the right to decide how many Palestinian refugees to take back.
"I tell those that signed the Geneva Accord that Palestine (Israel and the occupied territories) will never be Jewish," Rantissi told a crowd including dozens of fighters.
Scores of Hamas fighters on Israel's wanted list turned out for Friday's rallies, having spent months dodging Israeli helicopter-gunship strikes and special forces.
"I tell the Palestinian people not to be deceived by the relative calm," Rantissi said. "Jihad is coming and Sharon and his Zionist gangs will realise Palestine has its own fighters."