The sources say the foreign ministry has established a legal team to deal with efforts by foreign groups to arrange the prosecution abroad of Israelis involved in the war against Hezbollah guerrillas and crackdowns on Palestinians.
A ministry memorandum issued to Israel's military and other government agencies urges officials to avoid belligerent remarks that could potentially be used to back up allegations they were complicit in excessive use of force in Lebanon or Gaza.
"The type of language now considered off-limits includes 'crushing' the enemy, and 'cleansing', 'levelling', or 'wiping out' suspected enemy emplacements," a political source who saw the memo told Reuters.
The source quoted the memo as censuring one official who called for Israel to respond to Hezbollah rockets strikes against the strategic port city of Haifa during the 34-day war by "getting rid of a village in Lebanon".
The foreign and justice ministries declined to comment.
According to the memo, numerous war crimes lawsuits against Israeli officials were being prepared. It cited venues such as France, Belgium, Morocco and Britain, but no further details were immediately available.
Three Moroccan lawyers said last month they were suing the Israeli defence minister, Amir Peretz, over the recent offensives.
Israel Radio reported that a Danish politician also tried to have Tzipi Livni, the foreign minister detained and prosecuted during a recent visit to Copenhagen but the request for an arrest warrant was turned down by prosecutors.
An Israeli cabinet minister said that while military officials had been singled out in foreign lawsuits, politicians were still largely immune.
"There is, without a doubt, an effort among various organisations to lash out at our officers and commanders," Isaac Herzog, the tourism minister, told Israel's Army Radio by telephone during a visit to Finland.
"Of course this does not affect the political echelons."
Israel says its armed forces act within international norms and accuses Hezbollah and Palestinian factions of inviting civilian casualties by operating within populated areas.
Meanwhile Ehud Olmert, the Israeli prime minister, denied rumours of a deal that would see Palestinian prisoners released in exchange for Corporal Gilad Shalit, the soldier captured by fighters in Gaza on June 25.
He was quoted as telling the defence and foreign affairs committee that "all the publications and information about the possible release of the kidnapped soldiers are false".
On Sunday, the Yediot Aharonot newspaper said that under secret talks negotiated by Egypt, Israel could release up to 800 Palestinian prisoners in return for Shalit.
Israel has demanded Shalit's unconditional release, but local media have reported that talks have been under way for several weeks.