GAZA (Reuters) - Tens of thousands of Palestinians including hundreds of gunmen rallied in Gaza on Thursday to mark the 30th anniversary of Hamas’s founding and its chief vowed to reverse U.S. President Donald Trump’s recognition of Jerusalem as Israel’s capital.

Earlier in the day, Israel shut its border crossings with Gaza in response to daily rocket fire from the Hamas-ruled enclave since Trump’s announcement on Dec. 6, which stirred anger across the Arab and Muslim world and concern among Washington’s European allies as well as Russia.

“We will knock down Trump’s decision. No superpower is capable of offering Jerusalem to Israel, there is no Israel that it should have a capital named Jerusalem. Our souls, our blood, our sons and our homes are a sacrifice for Jerusalem,” Hamas leader Ismail Haniyeh told the rally in Gaza City.

With gunmen from other Palestinian militant groups showing support for Hamas, Haniyeh added, “We are marching towards Jerusalem, sacrificing millions of martyrs along the way,” and the crowd repeated his chants.

Israeli aircraft struck three Hamas facilities before dawn after the latest rocket salvo, Israel’s military said. It said it targeted training camps and weapons storage compounds. Hamas usually evacuates such facilities when border tensions rise.

Two of the rockets fired by militants were intercepted by Israel’s Iron Dome anti-missile system and a third exploded in an open area of southern Israel. There were no reports of casualties on either side of the frontier.

The military said in a statement that “due to the security events and in accordance with security assessments”, Kerem Shalom crossing - the main passage point for goods entering Gaza - and the Erez pedestrian crossing would be shut as of Thursday. It did not say how long the closure would last.

ROCKET FIRE, AIR STRIKES

Around 15 rockets have been fired into southern Israel since Trump’s announcement. None of the projectiles has caused serious injury or damage.

The attacks have drawn Israeli air strikes that have killed two Hamas gunmen. Two other Palestinians have been killed in confrontations with Israeli troops during stone-throwing protests along the border.

Israeli cabinet minister Tzachi Hanegbi said on Israel Radio that while Hamas, which last fought a war with Israel in 2014, was not responsible for the rocket fire, it needed to rein in militants from “breakaway groups” or it would “find itself in a situation where it has to contend” with the Israeli military.

In Istanbul on Wednesday, a summit of more than 50 Muslim countries condemned Trump’s move and urged the world to respond by recognizing East Jerusalem, captured by Israel along with the West Bank in a 1967 war, as the capital of Palestine. Palestinians want East Jerusalem for the capital of a future state they seek in Israeli-occupied territory.

Trump’s declaration has been applauded by Israeli Prime Minister Benjamin Netanyahu as a recognition of political reality and Jews’ biblical links to Jerusalem, a city that is also holy to Muslims and Christians.

Nazareth, the Israeli Arab city where Jesus is thought to have been raised, has canceled some Christmas celebrations in protest at Trump’s move, officials there said.

There was no word from Bethlehem, the Palestinian West Bank town that is Jesus’s traditional birthplace, whether it was also weighing a cutback on its celebrations at a crucial time of year for the its tourist trade.