Israeli Prime Minister Ariel Sharon put a U.S.-backed Middle East peace plan on borrowed time after a pair of Palestinian suicide bombers killed two Israelis in blasts that shook a six-week-old cease-fire.

But the peace "road map" appeared to be in no immediate danger of collapse despite the sudden clouds over what has been a summer of content for ordinary Israelis enjoying a respite from three years of daily violence.

Israel refrained from immediate retaliation for Tuesday's bombings. Hamas, which claimed responsibility for one of the attacks, said it still stood by the truce it declared along with several other militant groups on June 29.

Hamas said its bombing was in revenge for Israel's "assassination" of two of its members in a raid on Friday in the Askar refugee camp in the West Bank city of Nablus.

Sharon told reporters: "Israel will not be able to continue in the (peace) process despite its strong desire to do so, if terrorism does not stop completely and the Palestinian Authority does not fulfil all its obligations."

He demanded Palestinian Prime Minister Mahmoud Abbas, who condemned the bombings in the Israeli town of Rosh Ha'ayin and near the Jewish settlement of Ariel in the West Bank, to dismantle militant groups as mandated by the peace plan.

A 43-year-old Israeli was killed in the explosion that wrecked a Rosh Ha'ayin supermarket and an 18-year-old died in the blast at a bus stop outside Ariel.

In Washington, Secretary of State Colin Powell told a group of Israeli and Arab students in a speech: "We will continue to move forward on the road map... We will not be stopped by bombs."

REVENGE FOR ISRAELI "ASSASSINATION"

An armed group within the al-Aqsa Martyrs Brigades, an offshoot of Palestinian President Yasser Arafat's Fatah movement, said it carried out the attack in the Rosh Ha'ayin supermarket, also in retaliation for Israel's Nablus attack.

Both bombers, one aged 21 and the other 17, came from Askar, where two civilians were also killed on Friday by Israeli troops. It was not immediately known if Hamas and the Brigades coordinated their attacks, which came within an hour of each other.

Abbas aborted a tour of Gulf states on Tuesday to return home because of the bombings.

"The Palestinian Authority will work hard to maintain the truce and quiet," the moderate Abbas, who coaxed militant groups into the suspension of attacks, told Reuters from Qatar.

But Palestinian officials have said a Palestinian Authority crackdown on militants would lead to civil war.

"Israel will continue to fight terror wherever the Palestinian Authority does not," Sharon said in a speech late on Tuesday to Jewish students from the United States. "We will exercise our right of self-defense."

But a senior member of Sharon's cabinet said despite the attacks, Israel had not given up on the two-month-old, "road map" that envisions creation of a Palestinian state by 2005.

"We are not prepared to come to terms with such attacks, but I do not believe we have reached the point where the Israeli government says it has failed in its efforts to achieve calm and to try to move forward in the (peace) process," Vice Premier Ehud Olmert told Channel One television.

Political fallout came fast, with Israel postponing a release of 76 Palestinian prisoners, some of whom were already on a bus that pulled out of a prison's gates and then reversed back inside after news of the attacks.

(China Daily   August 13,  2003)