Fearing terror groups would try to perpetrate a terror attack aimed at derailing the Annapolis peace talks, the entire defense establishment was placed on high alert Sunday as Prime Minister Ehud Olmert landed in Washington ahead of Tuesday's meeting with the Palestinians. Even on what police termed "the day after," officers at the National Headquarters said alert levels would continue out of concern that the publication of any agreement could launch a wave of attacks. Defense officials said there were currently 10 terror alerts regarding Palestinian plans to perpetrate an attack in the next few days. The IDF was also on high alert along the Lebanese border out of fear that Hizbullah will try to launch an attack to spoil the summit. IDF officers said that the military was placed on particularly high alert along the Gaza Strip security fence to prevent Hamas or the Islamic Jihad from trying to perpetrate a large-scale attack using an underground terror tunnel. Last week, the Southern Command expanded its operations to locate tunnels along the fence, and particularly near the Karni and Erez crossings. "There is no doubt that a terror attack this week would have consequences on the talks at the summit," a defense official said. "For this reason everyone - the Israel Police, the IDF and the Shin Bet (Israel Security Agency) are on a higher level of alert." Following a Sunday evening situation assessment during which police considered the implications of the Annapolis meeting on the security of civilians in the coming days, all of the police districts were raised to a level three alert - one below the maximum. Police were instructed to increase security operations to prevent terror attacks, focusing on what police termed "three security circles" - the Green Line area, entrances to cities and areas with a high concentration of people. The National Police headquarters listed cities considered particularly at risk, among them Jerusalem, mixed Arab-Jewish communities, and cities such as Sderot and Ashkelon that are already vulnerable to rocket fire from the Gaza Strip. During the next few days, drivers are likely to notice increased delays and more police officers while passing through checkpoints. In addition, an increased police presence will be visible in central urban areas and on major roadways. Representatives from intelligence and traffic units will work to set up a national coordination center based at the Jerusalem National Headquarters to ensure open lines of communication and cooperation among the different police districts and divisions. In addition, police emphasized their intent to crack down on the number of Palestinians working illegally in Israel, particularly on Sunday and Monday. In anticipation of the conference, Border Police teams worked throughout the weekend to round up the laborers, and succeeded in arresting 626 Palestinians, all of whom were taken back across the Green Line. Two people who employed the illegal laborers and 19 "drivers" were also arrested. Police emphasized that of those apprehended, 20 were wanted by the Shin Bet for questioning, and were held in custody pending their interrogations. Meanwhile, the IDF on Sunday killed three Palestinians in counter-terror operations in the Gaza Strip and the West Bank. A member of the Aksa Martyrs Brigades in Tulkarm was killed by an undercover Border Police unit and another wanted man was wounded when the pair tried evading capture. Police described the wounded operative - now in custody - as a terrorist "handler" and said he was suspected of ties to Hizbullah as well as to "various terror elements" in the Gaza Strip. The Border Police unit was involved in a gun battle against what police said were members of the Fatah-affiliated organization. One operative, Muhammad Kuzah, was killed in the gun battle. Police said that Kuzah was involved in a number of shooting incidents in the Tulkarm area and had planted what they described as "very strong explosive devices" targeting Israelis. An additional 15 suspected terror operatives were arrested in the operation. In Gaza, IDF troops killed two Islamic Jihad operatives who were spotted approaching soldiers near the border fence in the northern Gaza Strip. A rifle and vest were found on one of the bodies.