A leader of Israel's Islamic Movement, Raed Salah, has been arrested amid escalating tension in Jerusalem.
Sheikh Saleh's detention for suspected incitement follows two days of clashes.
Tensions over the complex containing the al-Aqsa mosque and the Western Wall have boiled over into rioting several times in the past two weeks.
Extra Israeli police have been deployed for a Jewish festival. Some Palestinian officials have accused Israel of trying to "Judaise" Jerusalem.
The religious site known as Temple Mount to Jews and Haram al-Sharif to Palestinians is hotly contested, and was the flashpoint that led to the Palestinian intifada, or uprising, which broke out in 2000.
Thousands of Israeli police patrolled Jerusalem ahead of a march marking the Jewish festival of Sukkot, which passed off without incident.
Sheikh Salah, who has been detained in the past, had recently called on Muslims to "defend" the mosque.
"He was arrested over his inflammatory statements in recent days and on suspicion of incitement," police spokesman Shmulik Ben-Rubi told AFP news agency on Tuesday.
Police believe Sheikh Salah's branch of the Islamic Movement - an Israeli-Arab Islamist group that has often in the past been accused of incitement - is behind the recent clashes.
Volatile situation
On Monday, minor clashes broke out at al-Aqsa mosque. Police said they had closed the mosque to male worshippers under the age of 50, after finding wheelbarrows full of stones inside the complex.
On Sunday, at least five Palestinians and four Israeli police were injured in clashes, again after police limited access to the mosque.
About 30 people were injured there a week ago, when Palestinians stoned a group of visitors.
On Tuesday the Palestinian Authority denounced Israel's plan to "take over Jerusalem and Judaise it".
Negotiator Saeb Erekat accused the Israelis of "lighting matches in the hope of sparking a fire".
Correspondents say the unrest comes at a time of growing frustrations among Palestinians.
US attempts to restart peace talks appear to have stalled over Israel's refusal to halt settlement building in the West Bank, including in East Jerusalem where the Palestinians want the capital of a future state.
Israel's right-wing Prime Minister Benjamin Netanyahu has allowed Jewish building and demolitions of Palestinian homes built without permits to continue in East Jerusalem.
He has made clear he is strongly opposed to any division of Jerusalem and does not regard Jewish homes and areas there as settlements, although under international law the area is considered part of the occupied West Bank.
http://news.bbc.co.uk/2/hi/middle_east/8292184.stm
