JERUSALEM (CNN) — Israeli forces and Palestinian demonstrators clashed Friday in Gaza and near a checkpoint separating the West Bank from Jerusalem, as protesters throughout the region marked Land Day.

Protesters hurled rocks as Israeli forces fired rubber bullets, stun grenades and tear gas at the Qalandia checkpoint.

Seventeen Palestinians were injured during the protest, said the head of the Ramallah medical complex, Dr. Ahmad Bitawi. He said they had sustained moderate injuries from tear gas and rubber bullets.

In Gaza, at least one man died of his injuries, and 25 people were hurt in various incidents, medical sources said.

Palestinians hold Land Day rallies every year to commemorate the death of six demonstrators in 1976. The rallies have become an annual expression of what Palestinians consider discriminatory Israeli policies.

This year, Land Day organizers have called for protests inside Israel, in the Palestinian territories, and in neighboring Egypt, Lebanon and Jordan.

Rallying under the slogan of a global march to Jerusalem, protest organizers have called for “freedom for Jerusalem and its people.”

Israeli forces have been placed on high alert as Palestinians and Arabs observe the day.

The Qalandia checkpoint was among the chief flashpoints Friday.

Mustafa Barghouti, an independent Palestinian lawmaker, said he was hit in the head and back by tear gas canisters as he and a group of peaceful protesters were making their way to the checkpoint. He is now at the hospital in Ramallah, he said.

An Israeli military spokeswoman, Lt. Col. Avital Leibovich, disputed that account, saying the Israel Defense Forces’ information indicated that he was hit by another Palestinian in the Qalandia refugee camp as he sought to “convince people to riot.”

Israeli military forces sprayed foul-smelling liquid and played ear-piercing sirens as crowd-control measures.

Outbreaks of violence were reported elsewhere in the West Bank and Gaza.

Medical sources in Gaza said 20 Palestinians were wounded as a result of Israeli fire at the Erez crossing near the town of Beit Hanoun, most in their lower bodies. One of them died of his injuries.

An Israel Defense Forces spokesman said troops had fired at the legs of demonstrators who approached the fence and burned tires.

Five protesters were injured by Israeli fire in a demonstration near the town of Khan Yunis, in southern Gaza, when they attempted to cross the security fence, Palestinian medical sources said.

An Israeli security official said demonstrators had continued to approach the fence despite being told to move back. Warning shots were fired, followed by live fire when this was ignored, the official said, and one man was shot in the feet.

A Palestinian protester was hit in the head by a tear gas projectile in Bethlehem and was evacuated to Hebron hospital in the West Bank in critical condition, said popular committee coordinator Mahmoud Zawahreh.

Zawahreh said hundreds of Palestinians and international activists had marched toward the Bethlehem checkpoint, trying to walk to Jerusalem peacefully, when they were hit with tear gas, rubber bullets and stun grenades from Israeli forces.

The violence flared when a number of Palestinian youths managed to break from the Palestinian Authority barricades and reach the crossing that separates Bethlehem from Jerusalem and started throwing stones, Zawahreh said.

Earlier, a spokesman for the Israel Defense Forces said 300 demonstrators were hurling stones and Molotov cocktails at Israeli forces in Bethlehem, without an Israeli response.

Jerusalem police spokesman Shmulik Ben Rubi said several men were arrested at the Damascus Gate in the Old City for throwing stones at police.

In preparation for the Land Day protests, Israel announced a 24-hour closure of the West Bank and imposed restrictions on Friday prayers at Jerusalem’s Al Aqsa mosque, barring men under age 40 from entering the site.

Thousands of police officers are deployed across the country with an emphasis on the north of Israel and Jerusalem, Israeli police spokesman Micky Rosenfeld said.

While protest organizers said they would be peaceful, Israeli officials expressed concern that anti-Israel extremists could hijack the rallies.

Israel’s police chief, Yohanan Danino, urged leaders of the Arab community to ensure that extremists did not commit provocations.

“We are coordinating the marches that are to take place throughout the day with the heads of the community and hope that things will be quiet without any sporadic incidents,” Rosenfeld said.

Israeli military chief of staff Lt. Gen Benny Gantz held special security assessments Friday with regional deputies along Israel’s borders in preparation for the events.

The Israeli army said it would do whatever it took to protect its borders and residents.

Demonstrations marking the anniversary of the Jewish state’s creation turned deadly last year when clashes between pro-Palestinian activists and Israeli forces left several dead. The clashes occurred on the Israeli-Lebanese border and the frontier line separating Golan Heights from Syria.

In southern Lebanon, about 1,000 protesters, most of them Palestinian, gathered by the Crusader-built Beaufort Castle on Friday to mark Land Day. Lebanese flags flew from flagpoles, with one big Hezbollah flag above them all.

“The Arabs have finally woken, and now things will change even there,” said Muhamed Yusif Abu Shaikh, 67, outside Sidon as he pointed south, to the border.

Sabri Saidam, adviser to Palestinian Authority President Mahmoud Abbas, told CNN that Land Day for the Palestinians “is a day of mourning and a day of anger representing their eagerness to see the liberation of their land.”

Palestinians are demonstrating for their children’s right to live in a prosperous, independent Palestinian state with East Jerusalem as its capital, he said.

“(Land Day) is also a call for the international community to recognize the rights of the Palestinians that have long been confiscated by Israel and the need for the implementation of U.N. resolutions, otherwise the cycle of protest against the occupation will continue.”

Palestinian negotiator Saeb Erakat said Land Day celebrates a right to freedom.

“The freedom defenders who will partake in these peaceful demonstrations and rallies around the world are marching for dignity toward Jerusalem. Together with them, Palestinians will continue their certain path toward national independence,” he said.

— CNN’s Matthew Chance and Kareem Khadder reported from the West Bank, Ben Wedeman from Lebanon, Talal abu Rahma from Gaza City and Kevin Flower from Jerusalem.