The second intifada was a period of intense Palestinian-Israeli violence that looks ready to repeat itself.

On Sept. 28, 2000, when Ariel Sharon, the then opposition leader, heavily guarded by Israeli soldiers and policemen, walked into Al-Aqsa Mosque in Jerusalem, the move was certain to provoke an angry reaction from the Muslim population who holds the mosque to be the third holiest site in Islam. It did. The five years of the intifada cost more than 4,000 lives, the vast majority Palestinian.

And it could happen again. The second intifada had another name: Al-Aqsa intifada. In recent weeks the locus of the Palestinian conflict has shifted to violent clashes with the name “Al-Aqsa” in it: Al-Aqsa Mosque crisis. For the most part, armed conflict and popular unrest have largely been limited to the Gaza Strip and the West Bank. But that all changed a few weeks ago when three Arab citizens of Israel killed two Israeli police officers with guns smuggled into the site. Israel responded by installing magnetometers to prevent a recurrence of the violence. Palestinians called the magnetometers a violation of the delicate status quo governing the site, setting off demonstrations, both peaceful and violent, and possibly inspiring the killing of three Israeli family members in a West Bank settlement by a Palestinian, plus an attack on the Israeli embassy in Amman.

Israel’s decision to deploy magnetometers was a response to the attack that killed the two police officers. The move did not, in Israel’s mind, represent a change in the status quo. But the extra security, along with security cameras, is to the Palestinians a symbol of oppression, a representation of the occupation. Any unilateral Israeli move at the site is so sensitive that any action taken there without Jordanian and Palestinian consent is virtually untenable. When the mosque complex was closed to worshippers, it elicited a strong negative reaction from those who regularly pray there and immediately fed into the Palestinian, Arab, and wider Muslim perception that the site is once again being besieged as Israel attempts to exert control over Haram Al-Sharif.

Jerusalem’s Muslim community resumed prayers inside the Al-Aqsa compound Thursday after Israel removed the controversial security measures from the entrance to the holy site.

The security measures are now the same as they were before the July 14 attack at the site, a victory of sorts for the Palestinians. But there was still violence on Thursday and there could be more.

A similar wave of violence broke out in September 2015 over Israeli encroachment on the holy site. It lasted for around six months, the time when Palestinians resorted to stabbings and car rammings.

More similar to today’s Al-Aqsa crisis is the second intifada. Both came amid a backdrop of discontent. Palestinians in the territories were then, as now, increasingly resentful over their lack of economic development as promised by peace accords. Now, as then, they have found that the superpowers did little to back them.

The intifada was an expression of a deep disappointment and frustration over the denial of basic rights for Palestinians caused by the occupation, including the right to free access to Jerusalem. It provided the perfect example of how frustration can boil over into violence.

It may well be the case that this latest crisis is defused. However, the underlying conditions in the Palestinian territories are beginning to generate unrest among those Palestinians living inside Israel. This trend, if it persists, has the potential to exacerbate the situation in the region.

Today’s Al-Aqsa crisis could provide one of the sparks that ignites a dangerous cycle of violence.