A shoe lies among debris as an Israeli police officer stands nearby at the site of a suicide attack outside the Jewish settlement of Ariel in the West Bank east of Tel Aviv today. A suicide bomber blew himself up at a bus stop near the entrance to the settlement, police said, killing on Israeli and seriously injuring two others. The attack took place shortly after another suicide bomber detonated an explosion outside a supermarket in the central Israeli town of Rosh Haayin, killing hte bomber and at least one Israeli. AP Photo

ROSH HAAYIN, Israel - Palestinian suicide bombers blew themselves up at a strip mall in Israel and a bus stop at Jewish West Bank settlement today, killing two Israelis, shattering a summer of relative calm and raising new doubt about the fate of a shaky Mideast truce.

The Islamic militant group Hamas claimed responsibility for the second of the two bombings, marking its first open violation of a unilateral cease-fire it declared June 29.

It was not immediately clear whether this meant the truce was over. Hamas political leaders in the Gaza Strip could not be reached for comment.

On Friday, Israeli troops raiding a West Bank bomb lab killed three Palestinians, including two Hamas members, prompting threats of revenge from the Islamic militant group's military wing. An Israeli soldier also died in that gun battle in the city of Nablus.

The first suicide bomber detonated outside a supermarket in the Tel Aviv suburb of Rosh Haayin, killing himself and at least one Israeli. "I saw fire and a cloud of smoke. They brought out an injured child and then his mother," said Avigail Josef, who sells lottery tickets in a booth just feet from the site of the attack.

A short time later, an attacker blew himself up at a bus stop near the entrance to Ariel, killing an Israeli and seriously injuring two others. Rescue services identified the dead and injured as teen-agers.

The Web site of Izzedine al Qassam, the Hamas military wing, claimed responsibility for the Ariel bombing. The bomber was identified as Islam Yousef Qafisha, 21, from the West Bank city of Nablus. The military wing said it carried out the attack in response to what it alleged were Israeli truce violations.

Israel accused Palestinian Prime Minister Mahmoud Abbas of not doing enough to prevent attacks. Under a U.S.-backed peace plan, the Palestinians must dismantle militant groups, but Abbas, also known as Abu Mazen, has said he will not confront Hamas, Islamic Jihad and Fatah's Al Aqsa Martyrs' Brigade. Abbas is currently touring Gulf states.

"The fact that Abu Mazen is circling the globe does not show a serious commitment to dealing with terrorism," said Israeli Cabinet minister Gideon Ezra.

In a first response, Israel called off the release of 76 Palestinians from Israeli jails. The detainees, none of them accused of anti-Israeli violence, had already boarded buses today morning when the convoys were ordered back.

However, it appeared unlikely Prime Minister Ariel Sharon would order a large-scale response. He did not change his itinerary today or convene his security Cabinet, as is customary after major attacks.

The Palestinian leadership condemned the bombings, but said the Israeli accusations were unfair. The Palestinian security chief, Mohammed Dahlan, said he will not permit truce violations and that suicide bombings harm the Palestinian interest.

In Rosh Haayin, a bedroom community not far from Tel Aviv, the bomber struck at the entrance to a supermarket and pharmacy in a small shopping center, leaving a mass of twisted blinds and shattered glass.

"We heard an explosion and I ran downstairs and saw smoke," a witness identified as Roni told Israel's Channel 2 television. "I saw the bomber ... only the upper part of him was intact, he was missing legs and arms. I saw a leg lying nearby."

Two bodies were found at the scene, one belonging to an Israeli and the other the bomber. Nine people were injured, one seriously, five moderately and three lightly.

The blast sparked a large fire in the supermarket in Rosh Haayin, which is only yards from the line between Israel and the West Bank. Firefighters with breathing equipment pulled casualties out of the shattered store.

In Ariel, the body of the dead Israeli lay spread-eagled at the side of the road, covered by a white plastic sheet. Police and soldiers with sniffer dogs searched for more explosives.

Regional police chief Uri Bar Lev said police had been on high alert after warnings of an attack in the area.Israel TV's Channel 10, citing a Palestinian security source, said Palestinian officials had warned Israel about the Rosh Haayin and Ariel attacks.

Israeli Foreign Ministry spokesman Jonathan Peled said the attacks showed the need to complete a security barrier between Israel and the West Bank. Israel says it needs the fence to stop attackers entering Israel, but it has been condemned by the Palestinians and criticized by the United States.