Tens of thousands of Hamas supporters rallied in Gaza on Wednesday to celebrate the Palestinian group's 24th anniversary and the strengthening of fellow Islamists in Egypt.

"We hope all Arab countries will come under Islamic control," said Umm Bashir al-Hetani, a woman in the crowd over which fluttered a sea of green Islamist flags.

Founded in 1987, Hamas, an Arabic acronym meaning the Islamist resistance movement, is an armed wing of the Muslim Brotherhood in the Palestinian territories.

In Egypt, the Brotherhood and other Islamist groups sought more gains in the second round of a parliamentary election on Wednesday in an army-led transition that began with the overthrow of Hosni Mubarak in February.

Addressing the rally, Hamas's Gaza leader Ismail Haniyeh said the Brotherhood and other Islamist groups had "spearheaded the Arab Spring" of political change in the region "either through direct confrontation with tyrannical regimes or through the ballot box".

Though Hamas sprang from the Muslim Brotherhood, it operates independently due to its location and the conflict with Israel.

Egypt's Muslim Brotherhood has renounced violence as a means of bringing about political change, but endorses it for those under foreign occupation.

"Resistance is the way and it is the strategic choice to liberate Palestine from the (Jordan) river to the (Mediterranean) sea and to remove the invaders from the blessed land of Palestine," Haniyeh told the crowd, which chanted: "We will never recognize Israel."

The rally, which Hamas said 350,000 people attended, was punctuated by sonic booms from Israeli warplanes overhead, familiar sounds in the Gaza Strip, where militants frequently fire rockets into Israel and Israeli aircraft carry out raids.

"Hamas, together with other stubborn resistance factions, will lead the people towards uprising after uprising until all of Palestine is liberated," Haniyeh said, referring to territory that includes the occupied West Bank and what is now Israel.

Hamas is regarded by the West as a terrorist group for its refusal to recognize Israel, renounce violence and accept existing interim Israeli-Palestinian peace deals.

The group has said it might agree to a long-term truce with Israel in return for the creation of a Palestinian state in the West Bank and Gaza Strip.

Hamas seized the Gaza Strip from forces loyal to Western-backed Palestinian President Mahmoud Abbas's Fatah movement in 2007. Implementation of an Egyptian-brokered Hamas-Fatah deal has been delayed by squabbling between the two sides.