Stone-throwing Jewish settlers drove off Israeli security forces sent to dismantle buildings at a wildcat settler outpost near the West Bank city of Ramallah on Friday, Israeli media said.
Army radio said that five border policemen were lightly wounded by rocks and one "right-wing activist" was arrested.
A military spokeswoman told AFP that a combined force of soldiers and police were sent to clear intruders from the Oz Zion outpost which was declared off-limits to civilians after buildings there were repeatedly demolished in the past by authorities and rebuilt by activists.
She had no knowledge of casualties or arrests and the border police spokesman made no comment.
The radio said that about 250 activists took part in the clash, in which security forces responded with stun grenades before withdrawing from the site, as the Jewish Sabbath began at sunset.
The website of Haaretz daily said that a renewed attempt to clear the outpost was likely after sundown on Saturday when the Sabbath ends.
Israel considers settlement outposts built without government approval to be illegal and often sends security personnel to demolish them. They usually consist of little more than a few trailers.
The international community considers all settlements built in the West Bank -- including east Jerusalem -- to be illegal.