Fearing retaliatory terror attacks following Tuesday's IDF operation in Jericho and the capture of terror leader Ahmed Saadat, Insp.-Gen. Moshe Karadi on Wednesday instructed the police to raise the level of alert to Level 3 - one notch before declaring a state of emergency. Defense Minister Shaul Mofaz also extended the closure, initially imposed on the territories over the Purim holiday, until Saturday night. Security officials said they were concerned terror groups would try and abduct soldiers or civilians in an attempt to force the release of Saadat and the other five wanted men apprehended in Jericho. Large police forces were deployed throughout the country, with an emphasis on city centers and particularly Jerusalem, where Purim festivities were marked on Wednesday. As expected, violence was quick to follow the IDF's Jericho raid. Twelve Kassam rockets were fired from the Gaza Strip into Israel on Wednesday. No one was injured and the IDF responded by firing artillery shells at the launch sites. A Palestinian was shot dead in the West Bank after he threw a firebomb at a Border Police unit west of Ramallah. The army said a second firebomb was found lying next to the dead man. Shots were also fired at Israeli cars traveling south of Nablus. No one was injured, but IDF troops searched for the perpetrators. Defense officials said they did not believe the Jericho operation would set off a new round of violence but the continued closure in the territories was a necessary precaution. After the raid, Saadat's organization - the Popular Front for the Liberation of Palestine (PFLP) - warned that "Israel would pay dearly for its actions." The Shin Bet (Israel Security Agency) continued interrogating Saadat, in addition to Karine A weapons ship paymaster Ahmed Shubaki and four other terrorists responsible for the 2001 assassination of tourism minister Rehavam Ze'evi. The six men surrendered Tuesday night after the Jericho prison they were being held in was besieged by the IDF. Of the close to 300 Palestinians arrested Tuesday, some 40 were taken into Shin Bet custody in addition to Ze'evi's killers and Shubaki. Saadat, security officials said, could be in possession of valuable information since he was suspected of involvement in terror activity over the past few years from his jail cell. "We want to know what he has been doing over the past few years which he spent behind bars," one security official said. "We are not interested in punishing him but in gleaning valuable information he might have in his possession."