Hamas police clashed with protesters in the Gaza Strip as Palestinians and Israeli Arabs held a series of demonstrations to mark "Land Day".

In Gaza City, hundreds of students began a protest march at Al-Azhar University but were stopped by Hamas police, who arrested a number of them, witnesses said, without saying how many.

And around 300 university students marched to the Square of the Unknown Soldier where their rally to mark both Land Day and to issue a call to end the divisions within the Palestinian national movement, was forcefully broken up by Hamas police forces, an AFP correspondent said.

A large number of police converged on the square and were seen beating several demonstrators and arresting others, he said.

There were no immediate details on casualties.

The rallies kicked off a day of demonstrations which are to take place across Israel and the Palestinian territories to mark Land Day, recalling an incident in 1976 when Israeli troops shot and killed six people during protests against land confiscations.

Also in Gaza hundreds of people waving banners and holding up pictures of Palestinian prisoners in Israeli jails had joined a sit-in near the northern town of Beit Lahiya for a demonstration called by the various factions, witnesses said.

Protesters were also gathering in the West Bank city of Ramallah, where loudspeakers called on young people to join a peaceful protest against the Israeli army's years-long closure of a road between Ramallah and Beit El, a key road linking the city to the northern West Bank.

In Israel, demonstrators were expected to gather for the main rally in the northern Galilee town of Arrabeh, which was to start at 2:00 pm (1200 GMT) and be attended by Arab Israeli MPs and leaders of the Higher Arab Monitoring Committee.

Many Arab Israeli schools were closed for the day, and Arab rights groups said shops and businesses in Sakhnin were observing a one-day general strike to mark the anniversary.

"Every school and institute in the Arab sector has committed to the strike," said Mohammed Zidan, head of the Higher Arab Monitoring Committee

Further south, another rally was to take place in Al-Araqib in the Negev, a Bedouin village that has been levelled several times by the Israeli police over the past eight months.

Zidan said this was the first time Israel's Arabs were organizing two separate protests on Land Day.

Israel has never recognised Bedouin claims of land ownership in the Negev and wants the population to relocate into seven government-planned townships.

Israel's Arab minority leads Land Day demonstrations every year to protest against discrimination and assert its solidarity with the Palestinians.