GAZA CITY, Gaza Strip (AP) — Gaza health officials say nine people, including three children, have died in a blast in the northern Gaza Strip.

The cause of the blast was not immediately known. It came as Gaza militants were firing rockets into Israel on Monday, and it was not clear if the people were hit by an errant rocket attack or an Israeli reprisal.

THIS IS A BREAKING NEWS UPDATE. AP’s earlier story follows below.

JERUSALEM (AP) — Hamas militants fired a large barrage of rockets into Israel on Monday, including one that set off air raid sirens as far away as Jerusalem, after hundreds of Palestinians were hurt in clashes with Israeli police at a flashpoint religious site in the contested holy city.

The early evening attack drastically escalated what already are heightened tensions throughout the region following weeks of confrontations between Israeli police and Palestinian protesters in Jerusalem that have threatened to become a wider conflict.

Shortly after the sirens sounded, explosions could be heard in Jerusalem. One rocket fell on the western outskirts of Jerusalem, lightly damaging a home and causing a brushfire. The Israeli army said there was an initial burst of seven rockets, one was intercepted, and rocket fire was continuing in southern Israel.

In an initial reaction, an Israeli drone strike killed a Palestinian in the northern Gaza Strip, Hamas media reported. The Israeli army said an Israeli civilian in the country's south suffered mild injuries when a vehicle was struck by an anti-tank missile fired from Gaza.

Abu Obeida, spokesman for Hamas’ military wing, said the attack was a response to what he called Israeli “crimes and aggression” in Jerusalem. “This is a message the enemy has to understand well,” he said.

He threatened more attacks if Israel again invades the sacred Al-Aqsa Mosque compound or carries out evictions of Palestinian families in a neighborhood of east Jerusalem.

Earlier, Israeli police firing tear gas, stun grenades and rubber bullets clashed with stone-throwing Palestinians at the iconic compound, which is Islam’s third-holiest site and considered Judaism’s holiest. Tensions at the site have been the trigger for prolonged bouts of violence in the past, including the last Palestinian intifada, or uprising. It was not clear if the current unrest would escalate or dissipate in the coming days.

More than a dozen tear gas canisters and stun grenades landed in the Al-Aqsa Mosque, as police and protesters faced off inside the walled compound that surrounds it, said an Associated Press photographer at the scene. Smoke rose in front of the mosque and the iconic golden-domed shrine on the site, and rocks littered the nearby plaza. Inside one area of the compound, shoes and debris lay scattered over ornate carpets.

In an apparent attempt to avoid further confrontation, Israeli authorities changed the planned route of a march by ultranationalist Jews through the Muslim Quarter of the Old City to mark Jerusalem Day, which celebrates Israel’s capture of east Jerusalem.

But tensions remained high.

More than 305 Palestinians were hurt, including 228 who went to hospitals and clinics for treatment, according to the Palestinian Red Crescent. Seven of the injured were in serious condition. Police said 21 officers were hurt, including three who were hospitalized. Israeli paramedics said seven Israeli civilians were also hurt.

The confrontation was the latest after weeks of almost nightly clashes between Palestinians and Israeli troops in the Old City of Jerusalem, the emotional center of their conflict, during the Muslim holy month of Ramadan. The month tends to be a time of heightened religious sensitivities.

Most recently, the tensions have been fueled by the planned eviction of dozens of Palestinians from the Sheikh Jarrah neighborhood of east Jerusalem where Israeli settlers have waged a lengthy legal battle to take over properties.

Israel’s Supreme Court postponed a key ruling Monday in the case, citing the “circumstances.”

Over the past few days, hundreds of Palestinians and several dozen police officers have been hurt in clashes in and around the Old City, including the sacred compound, which is known to Jews as the Temple Mount and to Muslims as the Noble Sanctuary.

An AP photographer at the scene said that early Monday morning, protesters had barricaded gates to the walled compound with wooden boards and scrap metal. Sometime after 7. a.m., clashes erupted, with those inside throwing stones at police deployed outside.

Police entered the compound, firing tear gas, rubber-coated steel pellets and stun grenades, some of which enterd the mosque.

Police said protesters hurled stones at officers and onto an adjoining roadway near the Western Wall, where thousands of Israeli Jews had gathered to pray.

The tensions in Jerusalem have threatened to reverberate throughout the region and come at a crucial point in Israel’s political crisis after longtime leader Prime Minister Benjamin Netanyahu failed to form a governing coalition last week. His opponents are now working to build an alternate government.

Before Monday's rocket attack on Jerusalem, some 100 kilometers (60 miles) north of Gaza, Palestinian militants had fired several barrages of rockets into southern Israel. Protesters allied with the ruling Hamas militant group have launched dozens of incendiary balloons into Israel, setting off fires across the southern part of the country.

The rare strike on Jerusalem came moments after Hamas had set a deadline for Israel to remove its forces from the mosque compound and Sheikh Jarrah and release Palestinians detained in the latest clashes.

Hamas, an Islamic militant group that seeks Israel's destruction, has fought three wars with Israel since it seized power in Gaza in 2007. The group possesses a vast arsenal of missiles and rockets capable of striking virtually anywhere in Israel.

The rocket strike on Jerusalem was a significant escalation and raised the likelihood of a tough Israeli response. Though Israel's response thus far has come under growing international criticism.

The U.N. Security Council scheduled closed consultations on the situation Monday.

Late Sunday, the U.S. National Security Adviser Jake Sullivan spoke to his Israeli counterpart, Meir Ben-Shabbat. A White House statement said that Sullivan called on Israel to “pursue appropriate measures to ensure calm” and expressed the U.S.’s “serious concerns” about the ongoing violence and planned evictions.

Prime Minister Netanyahu pushed back against the criticism Monday, saying Israel is determined to ensure the rights of worship for all and that this “requires from time to time stand up and stand strong as Israeli police and our security forces are doing now.”

The day began with police announcing that Jews would be barred from visiting the holy site on Jerusalem Day, which is marked with a flag-waving parade through the Old City that is widely perceived by Palestinians as a provocative display in the contested city.

Just as the parade was about to begin, police said they were altering the route at the instruction of political leaders. Several thousand people, many of them from Jewish settlements in the West Bank, were participating.

In the 1967 Mideast war in which Israel captured east Jerusalem, it also took the West Bank and Gaza Strip. It later annexed east Jerusalem and considers the entire city its capital. The Palestinians seek all three areas for a future state, with east Jerusalem as their capital.