Twenty Palestinians, nine of them children, were killed in Israeli bombing attacks in the Gaza Strip on Monday night.

This came at the end of a day of violence that began in occupied East Jerusalem, where Israeli forces assaulted worshippers at the al-Aqsa mosque compound, injuring hundreds.

Scenes of brutality in Jerusalem generated outrage and solidarity among Palestinians and around the world.

The military wing of the Palestinian resistance organization Hamas issued an ultimatum giving Israel an hour ' until 6 pm local time ' to withdraw its forces from al-Aqsa and the occupied East Jerusalem neighborhood of Sheikh Jarrah, and free detainees.

When the deadline passed, resistance groups in Gaza fired volleys of rockets towards Jerusalem for the first time since the summer 2014 war, prompting celebrations from some Palestinians.

Israelis who had been gathering for the so-called Jerusalem Day march ran for cover as sirens sounded.

No serious Israeli casualties were reported.

A Hamas spokesperson in Gaza said that resistance fighters 'fired rockets at occupied Jerusalem, in response to the enemy's crimes and aggression against the holy city, and its abuse of our people in Sheikh Jarrah and al-Aqsa mosque.'

'Israel will respond with great force,' Israeli Prime Minister Benjamin Netanyahu said, adding that 'whoever attacks us will pay a heavy price.'

Such warnings should be understood as threats of collective punishment against civilians in Gaza.

Israeli ministers approved an aerial offensive against the territory, with an Israeli military spokesperson sayingthat the assault 'will take a few days.'

The Palestinian health ministry in Gaza reported that 20 people in the besieged territory were killed in Israeli airstrikes.

Nine children were among those killed, Palestinian media reported.

Israel claims that three Hamas fighters were killed in one of its airstrikes and Hamas said one of its commanders was killed.

Israel also reportedly closed Gaza's sole commercial crossing and further restricted access to the Strip's coastal waters.

Before Hamas' ultimatum, Israel had suffered a humiliating setback in its effort to assert control over occupied East Jerusalem.

Monday was supposed to be the day thousands of extremist Jewish settlers marched through the Old City to mark so-called Jerusalem Day.

This annual parade is a grotesque display of racism and provocation in which Israelis celebrate their 1967 occupation of the eastern part of Jerusalem.

This year's march was slated to take place amid heightened tensions and resistance against Israel's efforts to expel dozens of Palestinian families from their homes in the Sheikh Jarrah neighborhood as part of the ongoing ethnic cleansing and Judaization of Jerusalem.

For much of the day, Israeli police maintained that the settler march would proceed on its planned route through the Damascus Gate and into the narrow alleys of the Old City, including its Muslim Quarter.

By afternoon, however, and after recommendations from Israel's military and the Shin Bet, the state's domestic spying and torture agency, Netanyahu decided to reroute it before it was canceled altogether.

It was a striking victory for Palestinians, though one that came at a high price in injuries from the indiscriminate Israeli violence.

Before dawn on Monday, thousands of Palestinians headed to the al-Aqsa mosque compound to pray at the site and protect it from expected incursions by Jewish extremists and the kinds of violent assault by occupation forces witnessed on Friday and Saturday, when hundreds of Palestinians were injured.

Among the 90,000 Palestinians who gathered at al-Aqsa on Saturday to mark Laylat al-Qadr, one of the holiest nights of Ramadan, were thousands of Palestinian citizens of Israel.

After Israeli police halted dozens of buses bringing worshippers to Jerusalem, many continued their journey to the city on foot.

As dawn broke on Monday, videos and photos shared on social media showed Palestinians preparing to defendthe mosque from a new assault that morning by barricading entrances with furniture and gathering rocks.

Just after 8 am, occupation forces launched an assault on the compound, firing volleys of stun grenades, tear gas canisters and rubber-coated steel bullets at Palestinians there, injuring worshippers, journalists and medics.

The Palestine Red Crescent Society said it attended to almost 400 injured people, with some 220 taken to hospitals.

At least seven Palestinians were seriously hurt, some requiring surgery.

Forces also attacked the women's prayer area near Bab al-Rahma, the eastern gate of the compound which has been mostly sealed by Israeli authorities since 2003:

Israeli weaponry caused damage inside mosques in the compound:

Palestinians collected empty tear gas canisters, stun grenades and rubber-coated steel bullets and shaped them into an image of the Dome of the Rock and the word 'Jerusalem':

Yet despite this extreme and indiscriminate violence, Israel's police chief Kobi Shabtai told media on Monday night that his forces had been too restrained and that it was time to take off the 'kid gloves.'

Among hundreds of Palestinians injured by Israeli forces on Monday were reporters.

This video shows Israeli soldiers cornering Palestinian photojournalist Faiz Abu Rmeleh and beating him on his head:

Abu Rmeleh, whose photos have previously been published by The Electronic Intifada, was also assaulted by occupation forces in 2017.

The Palestinian news outlet Al Qastal said three of its reporters were injured by rubber-coated steel bullets and tear gas.

Another Palestinian bleeding from his eye was carried by medics who told an Anadolu Agency reporter that the injured man was a journalist:

The Palestine Red Crescent Society said Israeli forces prevented their medics from entering the al-Aqsa mosque compound where dozens of wounded Palestinians needed medical attention.

A Palestinian doctor from Jerusalem who came to assist the injured said soldiers prevented him from entering the compound 'from every gate':

Quds News Network reported that Israel attempted to expel Palestinian medics from the compound.

Rescue workers were also among the scores injured inside.

Israeli forces shot Palestinian paramedic Ahmad Dweikat with a rubber-coated steel bullet under his eye:

Israel's highest court tried to defuse growing resistance to the ethnic cleansing of Palestinians by delaying a hearing on the forced expulsion of three families from their homes in the Sheikh Jarrah neighborhood on Sunday.

Israel is applying openly discriminatory laws in an effort to force Palestinians out of their homes so they may be handed over to Jewish settlers.

A high court judge said the hearing would be rescheduled within a month and Palestinian families would be able to stay in their homes until a decision is made.

Israeli courts have consistently ruled in favor of settler groups to expel Palestinian families from homes in occupied East Jerusalem.

Settler organizations, backed by Israel's state apparatus, are unlikely to abandon their efforts to ethnically cleanse the city of Palestinians.

The goal, however, is to do it quietly, without the commotion that comes with an international outcry.

Egypt, Qatar and the United Nations were reportedly mediating between Hamas and Israel to slow the escalation of hostilities.

The US government expressed its deep concern over 'violent confrontations' in Jerusalem but reserved explicit condemnation for rockets fired from Gaza.

Washington's mission to the UN Security Council reportedly prevented the release of a joint statement condemning violence in Jerusalem.

The European Union's envoy to Israel meanwhile said he was 'extremely concerned over the violence in Jerusalem but only said that the firing of rockets was 'totally unacceptable and needs to stop.'

Electronic Intifada

Cover Photograph: Palestinians in al-Bureij, central Gaza, burn tires along the boundary with Israel while protesting in solidarity with Palestinians resisting evictions and police violence in Jerusalem, May 9. Ashraf AmraAPA.

Young men smile while holding flags and standing next to a fire at night