Tel Aviv, Israel ? Two Palestinian suicide bombers set off back-to-back blasts Sunday in a central Tel Aviv area crowded with foreign workers, killing 23 bystanders and wounding more than 100 in the bloodiest attack in six months.

Hours later, Israeli attack helicopters fired at least four missiles at metal workshops in Gaza City, witnesses said. Eight people were slightly injured. The Israeli military said the workshops were used for making weapons, including mortars and rockets.

In Rafah, on the Gaza-Egypt border, Israeli forces destroyed a house belonging to an Islamic Jihad leader, Palestinians said.

The Al Aqsa Martyrs’ Brigade, a militia linked to Yasser Arafat’s Fatah movement, said the suicide bombers were its members. Earlier, the militant Islamic Jihad claimed responsibility.

The twin blasts came just three weeks before Israel’s Jan. 28 general election and could boost support for hardline parties, including Likud, the party of Prime Minister Ariel Sharon.

Sharon convened an emergency meeting of key Cabinet ministers Sunday evening. Israel responded to two similar attacks in June — Jerusalem bus bombings that left 26 dead — by reoccupying most West Bank towns.

But with Israeli troops still in control of Palestinian population centers, Israel’s range of additional responses is limited, particularly as the United States considers a possible strike against Iraq and wants to avoid friction with the Arab world over the Israeli-Palestinian conflict.

The blasts were a setback to Egypt’s efforts to persuade Hamas and Islamic Jihad to halt attacks on Israeli civilians, at least until after the elections. The bombings also ended a period of relative calm. Previously the last bombing inside Israel was Nov. 21, when 11 bus passengers were killed in Jerusalem.

The Palestinian Authority condemned Sunday’s attack, which occurred at about 6:30 p.m. in a pedestrian area filled with working-class shops and restaurants near Tel Aviv’s defunct central bus station. Both bombers had explosives strapped to their bodies.

One blew himself up near a fast-food restaurant called “McChina.” The explosion ripped through the outdoor restaurant, overturning wooden picnic tables and showering glass on the sidewalk.

Seconds later, the other bomber blew himself up in a commercial area about 100 yards away.

A group of women, one carrying a baby, are directed to safety by Israeli police at the scene of a double suicide bomber attack in Israel. The bombing Sunday in downtown Tel Aviv killed at least 23 bystanders.

Rescue workers said most of the dead were foreigners, thousands of whom live in the area. Several of the wounded were treated on the sidewalk.

“I saw a man without a leg. I saw horrible things, people without legs, without arms. I saw fingers,” a witness who gave only his first name, Tomer, told Channel Two television.

Yitzhak Teva, a barber who was slightly injured, said he was cutting hair when the blast went off. “Half the wall fell on me and I was covered in broken glass,” Teva said. “I shut the shop and then there was the next explosion.”

Traffic jams in the narrow alleys around the old bus station hampered the evacuation of the wounded. Bystanders helped remove the injured with improvised means, using doors torn from their hinges as makeshift stretchers.

In broadcast appeals, police told illegal workers they had nothing to fear if they sought treatment or checked on friends.

“Please don’t be afraid to go to one of the Israeli hospitals in Tel Aviv, even if you are working illegally,” one announcement said.

President Bush was informed about the bombing by Condoleezza Rice, his national security adviser, who accompanied him home to Washington from Texas aboard Air Force One, said White House spokeswoman Claire Buchan.

“He condemns this in the strongest possible terms, ” Buchan said. “There are those who want to derail the peace process, but the president will not be deterred. Innocent people have a right to live in safety.”

In the past 27 months of fighting, Palestinian militias have carried out scores of bombings in Israel, and Sharon has held Arafat responsible by virtue of inaction. Palestinians say Israel’s military strikes have rendered the Palestinian security services helpless.

A Palestinian Authority statement pledged “to follow all those who planned and were behind these attacks. Such attacks against civilians are against the Palestinian national interest and violate all decisions taken by the Palestinian Authority (and) must be stopped.”

Claiming responsibility for the Tel Aviv blasts, the Al Aqsa Martyrs Brigades named the attackers as Samir Nouri, 19 and Burak Khelfeh, 20, both from the West Bank city of Nablus.

Egypt and Fatah have been trying to persuade Islamic Jihad and the larger Hamas to halt attacks on civilians in Israel. Talks in Cairo were to resume next week, but it was not clear if they would after Sunday’s attacks. Israel TV said Egypt was planning to issue an ultimatum to Hamas to comply.

Abdel Aziz Rantisi, a Hamas spokesman, said “resistance will continue.” The Israelis, he said, “are killing us day and night, so they should pay the price of their crimes.”

Since violence erupted in September 2000, 2,029 people have been killed on the Palestinian side and 714 on the Israeli side.