Clashes between Palestinians and Israeli security forces rocked the Al-Aqsa mosque in Jerusalem for a third straight day on Tuesday.

The site, considered holy by both Muslims and Jews, has long been a point of contention in the volatile region. And the violence of the past three days at the site is said to be the worst yet, Azzam Khatib, director of endowments and Al-Aqsa Mosque affairs, said, according to Al Jazeera.

"Because of the Palestinians who were present inside the mosque, Israeli police faced trouble storming it around 7:30am this morning. Police used teargas, rubber bullets, and stun grenades," Khatib said.

The mosque gates have reportedly been closed and Israeli police sealed off the scene. As of early Tuesday, at least 16 Palestinians were injured, Al Jazeera reported, citing Suleiman Ahmad, president of Jerusalem's Affairs Department, who was at the scene. 

"They have placed snipers on the rooftops and are using rubber bullets," Suleiman added.

Young protesters gathered at the mosque compound threw stones at a large number of police forces, who lobbed stun grenades in response, according to Agence France-Presse. A spokeswoman told AFP that Israeli police were trying to disband the stone-throwers, claiming there were no casualties or arrests yet.

Israeli police officials said Monday that they entered the hilltop mosque compound to prevent Muslim youths from harassing Jewish people and tourists during visiting hours, adding that they were aiming to deter what they called Palestinian “stone-throwers.”

The Al-Aqsa mosque is the third holiest site in Islam. The site is revered by Muslims as the Noble Sanctuary and by Jews as the Temple Mount. Rules governing the site allow Jews to visit but not pray and demonstrators fear that Israel may alter the current regulations.

The ongoing violence has grabbed the attention of leaders around the world and, on Tuesday, Turkish President Recep Tayyip Erdogan urged the U.N. to take action against Israel’s “breach,” Turkey’s state-run Anadolu Agency reported, citing a source from the president’s office.

The U.S. State Department also expressed concern about the clashes in the area.

"The United States is deeply concerned by the increase in violence and escalating tensions surrounding the (al-)Haram al-Sharif/Temple Mount," State Department spokesman John Kirby said, according to Reuters. "We strongly condemn all acts of violence. It is absolutely critical that all sides exercise restraint, refrain from provocative actions and rhetoric and preserve unchanged the historic status quo on the Haram al-Sharif/Temple Mount."