At least 22 people were killed and close to 100 injured, when two Palestinian suicide bombers blew themselves up, less than a minute apart, in a crowded area of south Tel Aviv yesterday.
The attack, in which both bombers were also killed, comes only three weeks before Israelis go to the polls, and is likely to shift the focus of the election from a corruption scandal in the ruling centre-right Likud Party, to the issue of security.
The area where the dual attack took place, on adjacent streets near the Old Central Bus Station, is home to thousands of foreign labourers, who are believed to be among the dead and injured.
The Al Aqsa Martrys' Brigade, which is associated with Palestinian Authority President Mr Yasser Arafat's Fatah Party, claimed responsibility for the attack in a leaflet. Earlier, there had been reports that the radical Islamic Jihad had carried out the bombings, but Mr Abdullah Shami, a leader of the movement in Gaza, cast doubt on the claim.
Israeli Prime Minister Mr Ariel Sharon blamed the Palestinian Authority for the attack, claiming that "all attempts to reach a ceasefire are failing due to the Palestinian leadership, which continues to support and initiate terror".
The Palestinian Authority condemned the suicide bombings as a "terrorist" attack, and said in a statement that it was determined "to confront firmly . . . the perpetrators of these attacks, the planners and whoever stood behind them".
Israeli helicopters fired at least three missiles at targets in Gaza City last night in the first apparent response to the bombings. Palestinians reported seeing helicopters hovering overhead and then the missiles streaking into targets on the ground.
Over the last year, Mr Sharon has responded to suicide bombings by sending the army back into Palestinian cities and by clamping lengthy curfews on large sections of the West Bank. Mr Sharon was meeting senior ministers late last night to discuss Israel's response to the attack. Some ministers were likely to demand Mr Arafat's expulsion from the West Bank. But commentators suggested that with a US attack on Iraq becoming increasingly likely, the prime minister would be careful not to take any measures that might inflame the region and undermine American efforts.
As after every bombing, practised first-aid and emergency workers descended on the site of the attack to evacuate the wounded. Eyewitnesses said buildings in the vicinity of the blast had been badly damaged.
"I heard the explosion, I felt the shockwave. I realised there would be many casualties. We looked for people who were breathing. I counted quite a few seriously wounded," said Alon Oz, an eyewitness.
Another man, who gave his name as Tomer, said he ran to help the injured. "I saw a man without a leg. I saw horrible things, people without legs, without arms. I saw fingers," he said.
Some of the injured foreign workers, fearing arrest and deportation because they are in Israel without a valid work permit, chose to stay away from the hospitals. Others, who helped evacuate the wounded, left them at the entrance to a nearby hospital and fled for fear of being detained.
Israel's Health Minister, Mr Nissim Dahan, issued a statement urging injured foreign workers to go to hospital for treatment and assuring them they would not be arrested. Television stations broadcast similar police appeals in English, assuring workers in the country illegally they would not be harmed if they sought treatment.
The suicide bombing was the first in an Israeli city since mid-November when a Palestinian blew himself up on a bus in Jerusalem, killing 11 people and himself.
A White House official said President Bush condemned the attack. "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," said spokeswoman Ms Clair Buchan.