Six Israeli police officers and five settlers were injured on Thursday in clashes that erupted as police dismantled an illegal settlement outpost, a police spokesman told AFP.

Police moved in to the Ali Ayan outpost in the West Bank, north of Ramallah, early on Thursday, spokesman Micky Rosenfeld said.

"Police, border police, and the army moved in there in the early morning in order to take down four illegal buildings that were built recently," he said. "Immediately upon arriving in the area there was a strong response from settlers, who threw stones."

He added: "Six police officers were injured lightly from stones and five settlers were also injured lightly (while) trying to attack police, who defended themselves."

Shortly afterwards, a firebomb was thrown at a parked police car which was destroyed. No one was inside.

"It happened a few kilometres away and was probably in response" to the outpost demolition, Rosenfeld said.

Six people were arrested in connection with the clashes and the firebombing.

On March 30, Israeli police arrested nine settlers after similar clashes at a settlement outpost in the northern West Bank.

Israel considers outposts built in the West Bank 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, which Israel captured from Jordan in the 1967 Six Day War, to be illegal.

Meanwhile Palestinians in the village of Madama, just south of Nablus, told AFP on Thursday that a group of settlers from the nearby Yitzhar settlement had deliberately set fire to Palestinian wheat fields.

The Israeli military confirmed it had received a complaint from Palestinians in the area and arrived to find Palestinians and settlers throwing stones at each other.

"Security forces arrived at the scene and dispersed the riot using riot disposal means," a spokesman told AFP."There was no injury or arrests as far as I know," he added.

He said the cause of a fire at the scene was being investigated.