The hardline Hamas and Islamic Jihad groups, as well as Palestinian leader Yasser Arafat’s Fatah faction and the Democratic Front for the Liberation of Palestine, announced they would suspend attacks against Israel for three months. A Fatah official said its armed offshoot, the Al-Aqsa Martyrs Brigade, would comply.Hamas and Islamic Jihad said their truce depended on ‘‘total cessation of all forms of Zionist aggression,’’ including Israeli military incursions, closures around Palestinian cities, a siege around Arafat’s presidential compound and ‘‘assassinations’’. Israel reacted frostily to the ceasefire announcement by Palestinian militant groups, saying it was not trustworthy and calling on Palestinian Prime Minister Mahmud Abbas to dismantle the ‘‘infrastructure of terror.’’‘‘We do not give any value to this announcement. Our only interlocutor to obtain the dismantlement of terrorist organisations is the Palestinian authority,’’ Prime Minister Ariel Sharon’s spokesman, Raanan Gissin, told AFP.Palestinian PM Abbas fears any attempt to dismantle the popular militant factions may spark civil war.‘‘All types of zionist aggression against the Palestinian people must cease immediately, from raids, to destruction, closure and siege on cities, villages and refugee camps, including the siege imposed on President Yasser Arafat,’’ Hamas and Islamic Jihad said in a joint statement.The groups also demanded the release of all Palestinian prisoners.