An Israeli police officer protects a Jewish driver who was attacked by Palestinian protesters near Jerusalem's Old City, Monday, May 10, 2021. Israeli police clashed with Palestinian protesters at a flashpoint Jerusalem holy site on Monday, the latest in a series of confrontations that is pushing the contested city to the brink of eruption. Palestinian medics said at least 180 Palestinians were hurt in the violence at the Al-Aqsa Mosque compound, including 80 who were hospitalized. (AP Photo/Ohad Zwigenberg)

JERUSALEM (AP) — Israeli Prime Minister Benjamin Netanyahu has accused the Hamas militant group of crossing a “red line” with its rocket attack on Jerusalem and promised a tough response.

“We will not tolerate an attack on our territory, in our capital, on our citizens and soldiers Whoever attacks us will pay a heavy price,” Netanyahu said Monday.

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

Hamas militants fired dozens of rockets into Israel on Monday, including a barrage 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 on Jerusalem drastically escalated the already heightened tensions throughout the region following weeks of confrontations between Israeli police and Palestinian protesters that have threatened to become a wider conflict.

The Israeli military responded with airstrikes in Gaza that killed at least one person, and officials warned of an open-ended operation against the territory’s Hamas militant rulers.

“We see this as a very severe attack on Israel, an attack that will not go unanswered,” said Lt. Col. Jonathan Conricus, a military spokesman. “Hamas bears full responsibility,” he added, saying Israel planned to deliver a “severe blow.”

Conricus said a total of 50 rockets were fired into Israel, including six that were aimed at Jerusalem, some 100 kilometers (60 miles) away. It was believed to be the first rocket attack on the city since a 2014 war.

Shortly after the sirens sounded, explosions could be heard in Jerusalem. One rocket fell on the western outskirts of the city, lightly damaging a home and causing a brush fire. The Israeli army said one rocket was intercepted and the others fell in open areas. Rocket fire on southern Israel continued throughout the evening.

Gaza health officials said nine people, including three children, were killed in an explosion in the northern Gaza Strip. It was not immediately known if the blast was caused by an Israeli airstrike or errant rocket fire. In a separate blast, Hamas media reported that an Israeli drone strike killed a Palestinian, also in the northern Gaza Strip.

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 from Gaza.

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