Tel Aviv - Israel has arrested Meir Ettinger, who tops the Shin Bet internal security organisation's list of most-wanted Jewish extremists, as part of a crackdown following last week's settler arson attack that killed a Palestinian baby.Ettinger, the 24-year-old grandson of late Jewish extremist Rabbi Meir Kahane, is scheduled to appear before a court in the northern town of Nazareth to have his remand extended, police spokeswoman Luba Samri said on Tuesday.He was arrested late Monday for alleged involvement in "criminal nationalist activity." she said.Israeli-Palestinian tensions have soared since suspected Jewish extremists threw a fire bomb into the home of a Palestinian family in their northern West Bank village, killing a boy and critically injuring his 4-year-old brother and both parents.A 27-year-old Israeli woman was moderately injured late Monday when suspected Palestinians threw a firebomb into her car at an East Jerusalem junction. The woman rolled out of her car, which went up in flames and continued moving, and was taken to hospital with 25-per-cent burns, medics said.Kach partySuspected Palestinians also threw firebombs at four civilian Israeli cars south of Jerusalem.Some three people were also injured in a clash on Jerusalem's flashpoint Temple Mount / Noble Sanctuary, which houses the Aqsa and Dome of the Rock mosques, as well as the ruins of the Biblical Jewish Temple.A Christian French tourist visiting the mount waved an Israeli flag on the site, sacred to both Muslims and Jews, police said.That is a violation of a Jewish-Muslim status quo agreement, under which non-Muslims are allowed to enter the mount, but may not pray there, nor display nationalist symbols.Four furious Muslims assaulted the flag-waver, who was lightly injured on the head and detained and removed from the mount for the status quo violation, Samri said. The four attackers were also detained, she said.The official Palestinian Wafa news agency said two of them were also lightly injured and six detained.Kahane was the founder of the ultra-right Kach party, which was outlawed by Israel as a terrorist organisation in the 1980s. He was shot dead by an Arab gunmen in a New York hotel in 1990.The Y-net news site published a document in which Ettinger purportedly advocated attacking Palestinians and vandalising sensitive Muslim and Christian holy sites, in order to create a major "revolution" and bring down the state of Israel.Ettinger has been arrested multiple times in the past and served restraining orders banning him from entering the West Bank. He had been living in Safed, northern Israel.New measures approved by Prime Minister Benjamin Netanyahu's security cabinet could mean that prosecutors have more success in keeping him behind bars.Among others, the security cabinet authorised administrative detention orders for Jewish extremists. Commonly used against Palestinian militants, administrative detention allows the arrest of a person deemed a security risk, even before he commits a crime.Attorney Yuval Zemer slammed the arrest as a "public relations" stunt, in the wake of the arson attack in the West Bank village of Douma.