The defense establishment expressed satisfaction over the weekend with the successful targeted killing late Thursday night of four terrorists, including Jamal Abu Samhadana - the leader of the Popular Resistance Committees who has been behind most of the recent Kassam rocket attacks on the western Negev. Labor MK Ami Ayalon, former head of the Shin Bet (Israel Security Agency), said Friday that the IDF had done the right thing by killing Samhadana. "Samhadana had to go," Ayalon said. "He was involved in terror attacks, one of the few who never tried to hide it." Samhadana's killing, security officials said, was meant to send a message to the Hamas leadership that Israel would act against anyone involved in terrorist attacks. "Nobody is immune," an officer said. "Just like we killed Samhadana, we will get our hands on each and every Palestinian behind terror attacks against Israel." IDF sources said Samhadana and the three other men were training for a planned terror attack when IAF missiles struck their base near Rafah in the southern Gaza Strip. On Thursday, Defense Minister Amir Peretz had ordered the IDF to step up targeted killings of Palestinians involved in Kassam attacks. Samhadana was a key player in the rocket attacks and a suspect in the October 2003 bombing of an American diplomatic vehicle in the northern Gaza Strip that killed three US security guards. His appointment in April as director-general of the PA Interior Ministry angered both Israel and Fatah, and was eventually torpedoed by PA President Mahmoud Abbas. The Popular Resistance Committees vowed to avenge their leader's death with missile launches and suicide bombings. "The Zionists and Israelis have opened the gates of hell by assassinating Abu Samhadana," spokesman Abu Abir said. Palestinian officials also condemned the attack on the four gunmen. A spokesman for the PA Interior Ministry called it a "crime," while another official said, "Peretz proved he was a criminal just like [his predecessor Shaul] Mofaz."