Israeli warplanes struck the Gaza Strip early Saturday after repeated salvos of rocket fire into Israel followed a second night of clashes between Palestinians and police in Israeli-annexed east Jerusalem.

Thirty-six rockets were launched, the Israeli army said, the most in a single night this year, after Gaza's Islamist rulers Hamas voiced support for the east Jerusalem protests, which were fuelled by a Thursday march by far-right Jews.

Washington said it was "deeply concerned" by the escalating violence, while the European Union appealed for restraint.

The United States, which has taken a more even-handed approach to the Israeli-Palestinian conflict since President Joe Biden took office in January urged "calm and unity".

"The rhetoric of extremist protesters chanting hateful and violent slogans must be firmly rejected," State Department spokesman Ned Price tweeted.

Tensions have been running high in east Jerusalem over a ban on gatherings, and a series of videos posted online showing young Arabs attacking ultra-Orthodox Jews, and Jewish extremists taking to the streets to bully Arabs.

On Thursday, at least 125 people were injured when Palestinian protesters, angered by chants of "death to Arabs" from far-right Jewish demonstrators, clashed repeatedly with police.

Skirmishes broke out again on Friday when tens of thousands of Muslim worshippers left the city's revered Al-Aqsa mosque compound after night prayers and found themselves confronted by dozens of armed police, some on horseback.

Protesters hurled water bottles at police, who fired stun grenades to disperse the crowd.

Hundreds of Palestinians also gathered at the Qalandiya checkpoint between Jerusalem and the occupied West Bank, police said.