The bomb that tore through a Dan No. 240 bus in the central Israeli city of Bat Yam on December 22 was assembled in a pressure cooker and activated by cellphone, much like the devices that killed three people and wounded hundreds more during the Boston Marathon in April 2013, the Shin Bet investigation has revealed.

The internal security organization, after days of what it termed “intensive intelligence work,” managed to break the terror cell, arresting four Islamic Jihad operatives from Bethlehem and 10 other people, including at least one Bedouin citizen of Israel. A news blackout on the arrests was lifted late Thursday.

The bomb, which exploded at the corner of Mivtza Sinai and Katzenelson streets in the Tel Aviv suburb of Bat Yam, caused no injuries because an alert passenger had noticed the bag containing the device left unattended by the bus’s rear door. The driver evacuated the bus, and the device was detonated as an Israeli sapper attempted to defuse it. The bus was wrecked, but there were no injuries.

The four Islamic Jihad operatives, who had planned to carry out a second, bigger bombing in Tel Aviv, were named as Yusef Salamah, 22, Shehada Ta’amri, 24, Hamdi Ta’amri, 21 and Sami Harimi, 20. Shehada and Hamdi Ta’amri, brothers, have both served time in Israeli prisons; Hamdi, the younger of the two, is a Palestinian Authority police officer who was in the middle of officer’s candidate school in Jericho.

The remains of detonated pressure cooker bomb used in December's Bat Yam bus attack (Photo credit: courtesy of Shin Bet)

The remains of detonated pressure cooker bomb used in December’s Bat Yam bus attack (Photo credit: courtesy of Shin Bet)

According to information released by the Shin Bet, the bomb, consisted of two kilograms of improvised explosives surrounded by nails and screws and stuffed into a pressure cooker. This was a method akin to the one used by Boston murderers, brothers Dzhokhar and Tamerlan Tsarnaev. It was made popular by an al-Qaeda manual placed online.

The Bat Yam bomb was built by Salamah and the two brothers, and given to Harimi. On the morning of December 22, he took the bomb, in a black gym bag, and traveled south from Bethlehem to the South Mount Hebron region, near the northern reaches of the Israeli Negev, and snuck through a hole in the Israel-West Bank security fence along with a group of Palestinian workers.

The screws and nails, much like in Boston, were added to increase the killing and maiming range of the explosive (Photo credit: courtesy: Shin Bet)

The screws and nails, much like in Boston, were added to increase the killing and maiming range of the explosive (Photo credit: courtesy: Shin Bet)

Harimi, who had until recently worked illegally at the popular Abulafia Bakery in Jaffa, caught a ride with a Bedouin citizen of Israel, who earned money transporting illegals into Israel to work.

Bomber Sami Harimi (Photo credit: courtesy Shin Bet)

Bomber Sami Harimi (Photo credit: courtesy Shin Bet)

In Jaffa, the Shin Bet said, Harimi went to pray in a mosque and then boarded the 240 bus. He left the bag near the center of the vehicle and got off at an unspecified stop.

The Shin Bet said simply that he later called a cell phone stuck to the explosive device and detonated the bomb. Ronen Solomon, an intelligence analyst, added that, generally, an accomplice picks up the fleeing bomber by car and the caller detonates the device once out on the open road.

The Shin Bet said the call was placed “several minutes” after Harimi got off the bus. By that time, the bomb had been spotted, and the bus evacuated, averting the bombers’ intended heavy death toll.

This photo released by the FBI early Friday April 19, 2013, shows the Tsarnaev brothers, with Tamerlan on the right, walking through the crowd in Boston on Monday, April 15, before the explosions at the Boston Marathon. (photo credit: AP/FBI)

This photo released by the FBI early Friday April 19, 2013, shows the Tsarnaev brothers, with Tamerlan on the right, walking through the crowd in Boston on Monday, April 15, before the explosions at the Boston Marathon. (photo credit: AP/FBI)

Harimi, who was almost certainly caught on camera at some point, was arrested on December 26. During questioning, he revealed to the Shin Bet that the cell had planned another large scale attack in the Tel Aviv-Jaffa area in the days after the first attempt.

Hamdi Ta’amri, the PA officer-in-training, revealed under questioning where he had hidden 20 additional kilograms of explosives near his house in Bethlehem.

The Shin Bet said that the investigation was ongoing and that more arrests were likely in the future.