Jewish settlers broke into an Israeli army base in the occupied West Bank overnight and vandalised it following rumours that soldiers were going to evacuate some illegal settlements, the military said on Tuesday.
In a separate incident, a group of hardline settlers crossed into a military zone close to the border with Jordan during the night to demonstrate against Jordanian protests over an Israeli decision to shut a footbridge at Jerusalem's holiest site.
Security forces intervened to get them out of the area.
The incidents were a sign of escalating tensions between the army and hardline nationalist settlers, who believe they have a biblical birthright to live whereever they want in the West Bank -- land the Palestinians claim as theirs.
Israeli Army Spokesman Yoav Mordechai told Army Radio there had been a string of "grave incidents" in the West Bank after rumours spread of an imminent eviction of settlement outposts.
"Dozens of right-wing activists threw stones at Palestinian and Israeli army vehicles," Mordechai said, after which they entered an army base...cursed, threw paint bottles, punctured army vehicle tyres and smashed a car window."
The settlers had also thrown stones at a senior army commander. A police spokesman said one settler was arrested and that police hoped to find more of the attackers.
Mordechai said he thought the incursion next to the Jordan border and the subsequent attack on the army base near the Palestinian city of Nablus were connected.
"I don't believe in coincidences. I think that to mobilise over 100 people takes organisation. ...We will not allow such disturbances with people taking the law into their own hands," he said.
Some 300,000 Israelis live in the West Bank, which the government calls by its biblical name, Judea and Samaria.
The territory was captured in a 1967 war and is home to 2.5 million Palestinians. The World Court views settlements Israel has built in the areas as illegal. Israel disputes this, but has not sanctioned all the outposts that dot the land.
The army's main task in the West Bank is defending the settlers from Palestinian locals.