Palestinian youths have clashed with Israeli police who entered the al-Aqsa mosque complex in East Jerusalem.
The Palestinians are said to have barricaded themselves inside the mosque and thrown stones at police, who moved in to stop them.
Israeli media said the Palestinians had intended to disrupt visits by observant Jews to the Western Wall.
The mosque, one of Islam's holiest sites, is in the Temple Mount/Haram al-Sharif site also revered by Jews.
Palestinian media said the clashes were precipitated by the visit to the compound of dozens of Jews guarded by Israeli security forces, angering the youths on the site.
It occurred on the Jewish fast day of Tisha B'Av, which commemorates the destruction of the Biblical Jewish Temples on the compound, and which traditionally draws larger numbers of Jewish worshippers to the site.
The police said a number of officers were injured. There were no immediate reports of any Palestinian casualties.
Six Palestinians were arrested, an AFP news agency photographer reported.
"Masked rioters fled into the mosque and started to throw stones and blocks at police from inside al-Aqsa mosque," a police statement quoted by AFP said.
"They threw fireworks directly at police.
"In light of the severe confrontation and the escalating actions of the rioters and with the aim of preventing further injury to police... forces entered a number of metres inside and closed the doors to the mosque with the rioters inside, restoring order."
The holy compound is a source of religious and political tension between Israel and the Palestinians, and a frequent flashpoint for violence.