Thousands and thousands of Palestinian rallied in central Gaza City on Saturday to mark Hamas's 20th anniversary, Waving green flags and banners, throngs of Palestinians poured into Katiba Square in Gaza city ahead of the rally at which Hamas leaders Ismail Haniya, Mamoud Al-Zahar, Sa'id Siyam, Osama Al-Muzini, and tens others reaffirmed their commitment to stay on the road of resistance and keeping the Palestinian legal rights.

"Resistance and jihad (holy struggle) is the best path to the liberation of Palestine, not negotiations and meetings, sitting at round tables and exchanging smiles and chuckles with the Jews," Haniya told the crowd.

The rally was the largest show in the Palestinian history  to prove that Hamas still has the best popularity and people despite all the conspiracies.

Haniya calls for the unity of the Palestinian factions and said that Hamas is ready to dialogue with Fatah but "without conditions," accusing Abbas's government in the West Bank town of Ramallah of preventing a return to unity.

"We are for dialogue and we call for it and welcome it, but the door to dialogue there (in Ramallah) has been closed. We say there should be a dialogue with no winners, no losers, and no conditions," he said.

Meanwhile Palestinian security forces said they arrested at least 26 Hamas supporters in raids across the West Bank, the latest in a series of measures aimed at dampening the Islamists' power in the territory Abbas controls.

Hamas television said that supporters in Gaza streamed in from towns and villages all across the coastal territory, home to some 1.5 million people, in cars and horse-drawn wagons, blocking streets throughout the city centre.

Tens of thousands of veiled women, masked men and children waving Hamas flags mixed in the crowd, but the exact number of people attending the rally remained unclear.

A huge banner reading "We will not recognize Israel" was placed on the backdrop of the stage in defiance of Israel's closing of Gaza to all but essential humanitarian supplies.

Former minister and senior Hamas member Said Siam told AFP that the massive turnout "is the answer to those who say Hamas is losing ground."

And top Hamas leader Mahmud al-Zahar said that "our message to the world is that this movement cannot be destroyed.

"This celebration shows how in 20 years we have grown from a movement of 1,000 people to huge numbers," he told AFP.

"The roots (of Hamas) stretch into the heart of the nation and into every part of the land," Mushir al-Masri, a former parliamentarian, shouted to the crowd from the podium.

"Twenty years -- from the stone to the knife, from the bullet to the bomb, from the mortar to the rocket, and from the martyrdom operations (suicide bombings) to the tunnels of Hell."

Hamas's exiled leader Khaled Meshaal said in comments on Saturday that the Palestinians are capable of launching a new uprising against Israeli occupation like the intifadas of 1987 and 2000.

"Our people are capable of launching a third or fourth Intifada until victory is ours," the Damascus-based Hamas chief said.

Meshaal admitted that the  movement's 20th anniversary came amid "difficult circumstances and a painful situation for the besieged Palestinians in Gaza."