Israel is considering new security measures amid increasing threats from right-wing Israelis opposed to the planned pullout from the Gaza Strip.
Polls show that most Israelis support Mr Sharon's plan
Internal Security Minister Gideon Ezra has called for the arrest of those threatening Prime Minister Ariel Sharon and ministers who support his plan.
Several cabinet members revealed over the weekend that they are facing threats to their lives.
Right-wing Israelis are strongly opposed to the disengagement plan.
Mr Sharon on Sunday ordered his security services to plan for "reining in" extremists, Reuters news agency reports.
Mr Sharon is planning to pull out the 8,000 Jewish settlers from Gaza and the troops that protect them by the end of the year. Israel will maintain control of Gaza's borders, coastline and airspace.
Four West Bank settlements are also to be evacuated.
Polls show that most Israelis back the Gaza disengagement plan, but settler groups have mounted a campaign of protests against it.
Several Israeli ministers - including Transport Minister Meir Sheetrit and Infrastructure Minister Benjamin Ben-Eliezer - said over the weekend they had received death threats.
Mr Sheetrit received letters saying his wife and children would be killed if he continued to support the plan.
"You will attend the funeral of your children. We will murder your wife and you," said an excerpt of one letter published in the Yedioth Ahronoth newspaper.
The Jerusalem Post reported on Monday that as many as 84 senior officials have been put under protection amid concern for their lives.
"The situation we find ourselves in now, in which we invest lots of resources and time in investigating, is not working," Mr Ezra told the Jerusalem Post on Sunday, arguing that it was time to do more.
Many Jewish settlers accuse Mr Sharon of betraying them
"People [against] whom we have material - which is classified and cannot be brought to court - should be placed in administrative detention."
Administrative detention orders which allow for suspects to be kept in custody without trial have mostly been used for Palestinian militants so far, reports AFP.
Prominent Israeli figures and intellectuals have expressed concern over the threats.
"Wake up before it is too late," Dalia Rabin, the daughter of assassinated Israeli Prime Minster Yitzhak Rabin, wrote in the Yedioth Ahronoth daily.
"If we don't do enough now to stop the deterioration we will once again witness the horrible spectacle of the murder of another prime minister."
Rabin was killed in 1995 by an ultranationalist Jew opposed to his peace moves with the Palestinians.
Observers expect the pressure to rise further ahead of upcoming key votes, including a cabinet vote in March on the disengagement plan.