Jerusalem ? Israeli security forces have arrested a Palestinian who worked at Hebrew University, accusing him of planting a bomb that killed nine people in the university cafeteria including five Americans and belonging to a Hamas cell involved in suicide bombings, officials said Wednesday.

The suspect, a house painter, was part of a 15-member cell that included Palestinian residents of east Jerusalem, who carry identity cards allowing them free movement in Israel, the officials said. That prompted calls for tough measures to prevent attacks by Arab residents of the city.

In addition to the July 31 university blast, the group is suspected of having carried out several other attacks, including a suicide bombing at a Jerusalem cafe in March that killed 11 Israelis and a suicide bombing in a Tel Aviv suburb that killed 15 Israelis.

Five members of the cell, run by the Islamic militant group Hamas, have been arrested thus far four from east Jerusalem and one from a village near the West Bank town of Ramallah, the officials said on condition of anonymity.

The painter was identified as Mohammed Oudeh, of Jerusalem’s Silwan neighborhood. Familiar with the university, Oudeh chose the site for the bombing knowing that few Arabs frequented the cafeteria and that foreign students ate there, the officials said.

Oudeh received the explosives from accomplices in the West Bank town of Ramallah, where the cell command was located, security officials said. On the night before the attack, he jumped over the university’s fence and hid the explosives under a bush.

The next morning, he walked through the main gate using his employee’s permit, picked up the bomb and planted it in the cafeteria. He then left and detonated the explosives with a cell phone from a distance, the officials said.

After his arrest, Oudeh told investigators he was sorry for what he had done because so many people died. Other members of the cell who were arrested did not express remorse and some said they were proud of the attacks, the officials said.

The cell was uncovered Saturday as two of its members were on their way to Tel Aviv to carry out an attack, the officials said. One suspect was caught at a surprise checkpoint; another fled and was picked up by a third cell member. The fugitives were caught after a chase through Jerusalem.