The Palestinian Islamist Hamas movement on Wednesday marked its 24th anniversary with a rally in the Gaza Strip attended by tens of thousands of the group's supporters.

Addressing the rally, Hamas Prime Minister Ismail Haniyeh vowed to continue the resistance until the end of Israel's occupation. He told the crowd “Resistance is the way and it is a strategic choice to liberate Palestine from the river to the sea and to remove the invaders from the blessed land of Palestine.”

Organizers said 350,000 people attended the rally, which turned the Gaza City center into a sea of green Hamas flags.

Hamas was founded in 1987 during the first intifada, or uprising, as an offshoot of the Egyptian Muslim Brotherhood. Its charter says it was founded to “liberate Palestine from Israeli occupation and to establish an Islamic state in the area that is now Israel, the West Bank and the Gaza Strip.”

The group, regarded by the West as a terrorist organization, won a landslide victory in Palestinian elections in 2006 and took over Gaza from forces loyal to Palestinian President Mahmoud Abbas's Fatah movement in 2007, after months of factional unrest.