A total of 15 people were killed, as well as two bombers, in a twin suicide attack on two buses in the southern Israeli city of Beersheva on Tuesday, police said.
Medical sources said that more than 80 people had also been wounded in the explosions, the worst such attack in Israel since a massive suicide bombing in a restaurant in the northern port city of Haifa in October last year.
Police sources said a bomber had boarded each of the buses several moments before the explosions in the center of the city.
"This attack was carried out by two suicide bombers who carried their charges for three minutes on the buses before blowing themselves up," one source said.
The explosions went off shortly before 3 pm (1200 GMT) near the city hall, completely destroying one of the buses and setting the second on fire.
The two buses were 100 metres (yards) apart when the blasts occurred. Several charred bodies wrapped in plastic were still seen lying next to the remains of one of the vehicles.
Ten of those being treated in hospital were in either a serious or critical condition, said sources from Magen David Adom, the Israeli equivalent of the Red Cross.
The smell of burnt flesh clung in the air while pools of blood mingled with broken glass and personal effects on the road. A number of other cars had also been severely damaged by the explosion.
Yaacov Cohen, the driver of the second bus, escaped with minor injuries but managed to help rescue workers recover casualties.
"I was at the junction and suddenly I heard a huge blast and saw smoke everywhere," he said.
"I realised it was an explosion on a bus near me, so I stopped my bus and opened all the doors thinking: we should just flee. Suddenly there was another blast inside my bus.
"When I opened the doors, a lot of people managed to get out ... It's difficult to describe what I saw outside," he added.
Police spokesman Gil Kleiman said no specific warnings had been received prior to the blasts but said there had been "general warnings".
Initial reports said there had been a third explosion in a nearby shopping center but the police said it was a false alarm.
Israeli Prime Minister Ariel Sharon said his government would not relax in its "fight against terror" after the attack.
"We have to fight terror: that is what my government is doing. The struggle against terror will be pursued to the fullest extent," he said.
A spokesman for Hamas said in a phone call to its offices in the West Bank town of Jenin that the attack was carried out by members of its armed wing in response to the killing of two of its leaders, Sheikh Ahmed Yassin and Abdelaziz Rantissi, in air strikes earlier this year.
It was also intended as a show of solidarity with Palestinian prisoners who are currently on hunger strike in Israeli prisons, the spokesman added on condition of anonymity.
Negotiations minister Saeb Erakat said the Palestinian Authority condemned any attack which targeted civilians.
"The Palestinian Authority condemns attacks which target civilians, whether they be Israeli or Palestinian," Erakat said.
The attack came hours after Israeli guards manning the main crossing point between Israel and the Gaza Strip thwarted a suicide attack when they detained a man who had been carrying an explosives belt.
The last Palestinian attack in Israel was on July 11, when one young female soldier was killed in a blast at a bus stop.
Israeli foreign ministry spokesman David Saranga said the attack was proof of the Palestinian government's failure to crack down on militant organisations as laid down in the troubled roadmap peace plan.
"While Israel is trying to move forward by implementing the disengagement plan (which involves a withdrawal from the Gaza Strip), the answer of the Palestinian terror organisations is more attacks," he said.
"We call on the PA (Palestinian Authority), once again, to dismantle the terror infrastructure, to collect illegal weapons and to carry out their obligations under the roadmap."