Thousands of Palestinians took to the streets of the Gaza Strip and the West Bank on Tuesday to demand an end to the rift between the Hamas and Fatah factions that has left the two Palestinian territories in the control of rival governments.

"The people want an end to the division!" the demonstrators chanted in the largest such push to date. "National unity!"

The demonstrations were organized by young Palestinians who used Facebook to mobilize protesters, saying they were inspired by recent uprisings in neighboring Arab countries. But the rallies were quickly commandeered by Hamas in Gaza and by Fatah in the West Bank, with both groups dispatching supporters and sound trucks to voice their own calls for unity.

The Islamist Hamas movement seized power in the Gaza Strip in 2007, routing Fatah forces in a brief civil war. Fatah, the mainstream nationalist party, remains dominant in the West Bank, where the Palestinian Authority governs. Previous reconciliation efforts have failed, and there has been little evidence that either faction is ready to share power.

The largest rally was in Gaza City, at the Square of the Unknown Soldier, where throngs gathered under a sea of Palestinian flags. Hamas sent its supporters, waving the movement's green banners, which drove hundreds of people to a breakaway protest in another square.

Riding the wave of popular sentiment, Ismail Haniyeh, the prime minister of the Hamas government, invited Palestinian Authority President Mahmoud Abbas to Gaza for immediate unity talks. A Fatah spokesman in the West Bank promptly dismissed the call as "not serious."

In Ramallah, the seat of the Palestinian Authority, the rally at Manara Square was dominated by young Fatah supporters and government employees who were given time off to participate. No factional banners could be seen, only the red, white, black and green of the Palestinian flag.

Addressing the crowd, Mahmoud al-Aloul, a senior Fatah official, threw his arm around Hussein Abu Kweik, a Hamas leader, in a show of brotherhood. "We are one people," Abu Kweik said, calling for a "sincere national dialogue" that he said should lead to new parliamentary elections.

"Our enemy is the occupation," Aloul said, referring to the Israeli military presence in the West Bank. "We want unity so we can confront the occupation together."

Some younger protesters in Ramallah complained that the rally, planned by youth activists who say they have no political affiliation, had been hijacked by Fatah.

"Unfortunately, the persons responsible for this division are planning to attend this demonstration," said Mahmoud Kuhail, 26. "We're fed up with the speeches. If they want to end the division, Abbas can go to Gaza and shake hands with Haniyeh as a first step. They can take actual steps on the ground if they really want it."