Israel is growing concerned about a rise in terror activities by Jewish extremists against Palestinians and Israeli left-wing activists as it anticipates violence ahead of a possible United Nations recognition of Palestinian statehood.

A new report by the Shin Bet internal intelligence agency, whose contents were reported by the Haaretz newspaper yesterday, said that far-right settlers living in the occupied West Bank have become more systematic in their attacks by creating a database in which they collected information about potential targets. The agency also said pinning down such settlers was challenging because they operated in small groups that were difficult to track down.

The report added a new dimension to potential clashes just days ahead of a planned move by the Palestinian Authority to seek full membership during the UN General Assembly session that begins on September 19 in New York. Israel and the US have rejected the Palestinian plan and Barack Obama, the US president, said in his first public remarks on the issue on Monday that the bid was a "distraction" and would not result in viable statehood.

In what appears to be an attempt to lobby western governments to reject the Palestinian plan, the Israeli government has warned that such a step would trigger violent acts between Israelis and Palestinians as well as towards Israelis in other countries in the Middle East. Indeed, Israeli officials said that rioting at its Cairo embassy on Friday, in which protesters replaced the Israeli flag with Egypt's and tossed embassy documents out the window, was a possible preview to violence that it could face following the UN vote.

Now there is worry that tensions closer to home could also escalate.

In recent days, several attacks have taken place against both Palestinians in the West Bank and against Israeli soldiers, and left-wing activists within Israel proper in what appeared to be acts of revenge by settlers against the dismantling of a Jewish settlement.

On Monday, the home of a prominent Israeli activist of the anti-settlement group Peace Now was vandalised with spray-painted slogans referring to the demolition of Jewish homes in a West Bank settlement by perpetrators who, according to police, were tied to Jewish extremist groups.

The attack took place almost a week after the Israeli army razed three homes in Migron, a settler outpost that was not authorised by the Israeli government.

The graffiti sprayed on the door and stairway of the Peace Now activist included "Peace Now the end is coming" and "Migron price tag". The latter slogan referred to a so-called price-tag operation of retribution that militant settlers said they would exact for any curbs on settlement in the West Bank. The activist was quoted by Israeli media as telling police that she had also received threatening emails and phone calls recently with similar messages.

Also last week, just hours after the Migron demolition, a section of a mosque in the Palestinian village of Yatma, near Nablus, was set ablaze and the words "price tag" spray-painted on its walls in an attack that Palestinians accused settlers of carrying out. In another Palestinian village in the West Bank, two cars were torched.

Two days later, settlers launched a price-tag strike for the first time against an Israeli army base. Vandals broke into the base near the Palestinian city of Ramallah, slashing tires and breaking windows on 13 vehicles and daubing pro-settler graffiti on walls.

According to the Shin Bet report, settler extremists were acting in small groups that were difficult to infiltrate.

They carried out surveillance on Palestinian villages, collecting information on sites from which to access the communities and also sought escape routes. At the same time, they were also gathering information about left-wing Israeli activists living within Israel, the report said.

Peace Now, which tracks settlement activity in the West Bank, released a statement on Monday warning that settler groups were being encouraged to take action by ultranationalist members of the predominantly right-wing Israeli parliament.

It said that emergency steps were needed to counter "what seems like a new Jewish underground … the atmosphere of hate … is seeping from elements in the parliament deep into Israeli society".

The attacks by settlers against Palestinians in the West Bank and Jewish activists also came in parallel to what police described as growing violence against Palestinians living in East Jerusalem.

On Monday, a group of Jewish youths with long sidelocks and large skullcaps - typically worn by nationalist-religious settlers - approached two Palestinian sanitation workers at a Jewish neighbourhood in Jerusalem and sprayed tear gas at their eyes. In the same neighbourhood in the past two weeks alone, several cars of Palestinians working in a nearby bakery were vandalised, in one case the slogan "death to Arabs" was sprayed on one of them while other graffiti included the word "Migron" and a Star of David.