Israeli police have blamed "terrorists" for a bomb that exploded on a bus in the Tel Aviv suburb of Bat Yam only moments after passengers left the vehicle.
Police have called Sunday's attack the most serious strike since a bomb exploded and wounded 20 people in Tel Aviv in November 2012, at a time when Israel was fighting Palestinian rebels in the Gaza strip.
"Based on the findings at the scene by bomb disposal experts, it was a terrorist attack," said Micky Rosenfeld, a police spokesman. "We're continuing to search the area for suspects."
There were no deaths or injuries, Rosenfeld said. The blast blew out the windows of the bus and charred its sides.
The device was discovered in a bag on the bus, prompting the driver to quickly evacuate all passengers. The explosion happened shortly afterwards when a bomb squad expert was examining the bomb.
President Shimon Peres phoned the bus driver, Michael Yoger, to thank him for saving the passengers.
"The nation owes you a debt of gratitude and I would like to personally congratulate you for this act of bravery," Peres told Yoger.
A 'sensitive time'
Rosenfeld said the nature of both the target and the device indicated to authorities that "terrorists", and not criminals, carried out the attack. Although Rosenfeld would not elaborate on this comment and no one has claimed responsibility.
The explosion came at a sensitive time in Middle East peace efforts. Israel and the Palestinians resumed talks for the first time in almost five years last summer. But the US-brokered negotiations have made little headway.
"Violent acts targeting civilians are deplorable," said Jen Psaki, US State Department spokesperson. "We reaffirm our unshakable bond with Israel and our solidarity with the Israeli people."
A decade ago, Israel experienced an overwhelming number of Palestinian suicide bombings on buses, in restaurants and in other public spaces. More than 3,000 Palestinians and 1,000 Israelis have died in years of clashes between the two countries.