Two Palestinian terrorist groups threatened on Wednesday to call off a cease-fire with Israel if Palestinian leader Mahmoud Abbas persists with an arrest campaign he launched after Monday's suicide bombing in Netanya. Abbas's security forces have arrested at least 15 low-level operatives of Islamic Jihad, which was responsible for the attack. Two other terrorist groups, the Popular Resistance Committees and the Aksa Martyrs Brigades, issued a joint statement threatening to end the February cease-fire if the arrests continue. "We are ready to end the calm if the Palestinian Authority does not listen to this legitimate demand because the fight should be against the occupation and not to target the Palestinian resistance wings," the statement said. The PA remains determined to arrest those responsible for the suicide bombing, PA Interior Ministry spokesman Tawfiq Abu Khoussa said. "The campaign will continue. We are implementing an order and will fulfill our commitments," Abu Khoussa said. The arrest campaign has fallen short of Israeli demands, but still infuriates the terrorists and could shake up the PA ahead of January's parliamentary election. Nabil Abu Rudeineh, Abbas's spokesman, warned that renewed violence could have a negative impact on the upcoming election. The PA fears an Israeli crackdown would disrupt the voting, or even play into the hands of Hamas, Abbas's main rival in the elections. "We don't want to give Israel any pretext to escape from implementing its obligations. Giving Israel this pretext is not going to serve the Palestinian interest and the Palestinian election," Abu Rudeineh said.