Israeli riot police have fired tear gas to break up clashes in Umm El-Fahm where far-right Jewish protestors held a court-sanctioned march.
Angry residents threw stones at police who were deployed in their thousands for the rally in the northern Israeli town.
Police said 15 officers were hurt during the clashes and that three people had been arrested, while Israeli media said 16 people had been hurt, including an MP with the left-wing Meretz party and a deputy police chief.
Carrying Israeli flags, the protestors marched for 30 minutes under heavy police protection on the outskirts of Umm El-Fahm, prevented by the police and hundreds of angry residents from entering the town.
The Jewish demonstrators had petitioned the High Court to allow them to march in the city, a stronghold of the radical wing of the Islamic Movement in Israel, to demonstrate their right to march anywhere in Israel.
Among the leaders of the march is Baruch Marzel, who led the anti-Arab Kach party that was banned in 1994 and who has been questioned several times by police in connection with attacks on Arabs.
Another leader is Michael Ben Ari, an MP with the far-right National Union settler party.
Arab residents said the protest was meant to provoke and had to be stopped.
Israel's High Court signed off on the Umm El-Fahm march in October, but police then called off planned demonstrations on several occasions. The court ruled again in favour of a march in January.
Arabs make up about 20% of Israel's population of nearly 7.5m, and are the descendents of those who remained in Israel following the creation of the Jewish state and the 1948 Arab-Israeli war.
Elsewhere, Palestinian militants in Gaza fired a rocket at southern Israel for the first time in ten days, causing no casualties or damage.
The projectile struck an open area several kilometres from the border with the Hamas-ruled territory.
Militants have fired more than 190 rockets and mortar rounds at Israel since the end of the 22-day Israeli offensive in December and January that was aimed at halting the attacks.
In turn, Israel has launched several air strikes at suspected militants, weapons caches and smuggling tunnels along the Gaza-Egypt border.
UN says Israel violated human rights
UN investigators say Israel violated a range of human rights during its invasion of Gaza, including targeting civilians and using a child as a human shield.
The accusations come in reports to the UN Human Rights Council which also called for an urgent end to Israeli restrictions on humanitarian supplies to Gaza and a full international investigation into the conflict.
'Civilian targets, particularly homes and their occupants, appear to have taken the brunt of the attacks, but schools and medical facilities have also been hit,' said one report by Radhika Coomaraswamy, the UN Secretary-General's Special Representative for Children and Armed Conflict.
The Sri Lankan human rights lawyer visited the region in early February. She cited a long series of incidents to back her charges.
In one, she said, Israeli soldiers shot a father after ordering him out of his house and then opened fire into the room where the rest of the family was sheltering, wounding the mother and three brothers and killing a fourth.
In another, on 15 January, at Tal al Hawa southwest of Gaza City, Israeli soldiers forced an 11-year-old boy to walk in front of them for several hours as they moved through the town, even after they had been shot at.
An Israeli commander in the 22-day Gaza invasion said yesterday that Israel's efforts to protect troops from Palestinian fire may have contributed to unwarranted killing of civilians.
'If you want to know whether I think that in doing so we killed innocents, the answer is, unequivocally, yes,' Tzvika Fogel, a reserve brigadier-general said.
He added that such incidents were exceptional.
Investigation
Ms Coomaraswamy's comments formed part of a much longer report from nine UN investigators, including specialists, on the right to health, food, adequate housing and education and on summary executions and violence against women.
All cited violations by Israel, and in some cases by the Hamas Islamic movement that controls Gaza, during the invasion from 27 December until 17 January which Israeli leaders say was launched to stop rocket attacks by Hamas from the territory.
Palestinian officials say 1,434 people in Gaza, 960 of them civilians, were killed in the fighting - a figure Israel contested. The report from the nine investigators gave the total as 1,440, saying of these 431 were children and 114 women.
The overall report was criticised in the 47-nation Council by Israel's ambassador Aharon Leshno Yar, who said it 'wilfully ignores and downplays the terrorist and other threats we face,' and the use by Hamas of human shields.
Mr Leshno Yar said the 43-page document was part of a pattern of 'demonising Israel' in the Council where an informal bloc of Islamic and African nations usually backed by Russia, China and Cuba has a built-in majority.
Another report presented to the Council yesterday came from Robert Falk, a US academic and the body's special rapporteur on human rights in the occupied Palestinian territories.
Mr Falk, whom Israel barred from entry last year after accusing him of bias and prejudice, said Israel had subjected civilians in Gaza to 'an inhuman form of warfare that kills, maims and inflicts mental harm'.
His report, in which he called for an independent experts group to probe possible war crimes by Israel and Hamas and also suggested that the UN Security Council set up an ad hoc criminal tribunal, was issued late last week.
