Explosives-sniffing dogs, electronic warfare systems to jam bomb signals, and over 250 armed bodyguards will accompany every move US President George W. Bush makes in Israel, from the moment he lands at Ben-Gurion International Airport on Wednesday until he takes off on Friday. A defense official who used to serve in the Protective Security Unit of the Shin Bet (Israel Security Agency) said Tuesday that American security for the president far surpassed the level of security provided for the Israeli prime minister. "They don't trust anyone except themselves," the official said. "They have their own cooks, doctors, metal detectors, dogs and everything else." The IDF is closing off the West Bank for the visit - effective midnight Tuesday, until Saturday. For the duration of the closure, the IDF said, the passage of Palestinians in need of humanitarian aid will be authorized by the District Coordination and Liaison offices. American security teams began arriving in Israel last week ahead of Bush's visit, scouting out every road his convoy would travel as well as possible escape routes. Some 10,000 Israel Police will be deployed within Jerusalem over the next three days, securing the area around the King David Hotel and closing off the roads he will use. Roads were sniffed by explosives-detection dogs and scanned by an electronic-warfare system that can intercept transmissions to roadside bombs that might be activated by remote-control to target the convoy. The security teams also inspected every electrical pole and manhole along the routes Bush will take in Jerusalem. There will be two Air Force One planes in the country for the visit. One has already arrived, and the second will bring Bush on Wednesday. Two helicopters - including Marine 1 - have also arrived and will transport the president while he is here. The helicopters were flown to Israel via two large Galaxy transport planes and had their rotors reattached upon arrival. A US Navy aircraft carrier also arrived in Haifa earlier this week, carrying Chinook transport helicopters for use by the presidential staff, as well as fighter jets to secure Air Force One when in flight. "Everything is about decoys," the official said. "Which helicopter or plane he flies and which car he is in within the 20-car convoy." In addition, Bush will be accompanied by least three doctors, including a cardiologist, a trauma specialist and an anesthesiologist. Air Force One has rooms that can be used to perform complicated surgeries, the official said. In Ramallah, meanwhile, US snipers will take up positions on rooftops, and local traffic will be barred from some downtown districts, Palestinian security officials said Tuesday. Bush is expected to travel to Palestinian Authority President Mahmoud Abbas's Ramallah headquarters by helicopter on Thursday. Two alternate landing sites have been prepared, one in Abbas's Mukata compound and one in the parking lot of the nearby Quaker-run Friends' School. On Monday, helicopters practiced takeoffs and landings at both sites. During Bush's visit, a security cordon will be set up over a radius of some 300 meters around each landing site, said Palestinian police spokesman Adnan Damiri. "The area of the Mukata and the Friends' School will be closed to traffic, and we are asking people who live around the Mukata not to stand on the roofs of their buildings," he said. Interior Minister Abdel Razek Yehiyeh said parking would not be permitted in these areas. He said security arrangements were "unprecedented, due to the importance of the occasion and the importance of the visitor."