In the shadow of terrorist threats emanating from Hizbullah in the North to the Sinai Peninsula in the South, police districts around the country have gone on their highest level of alert ahead of Pessah holiday and Israel's 60th Independence Day celebrations, which follow soon afterward. During the first stage of preparations - which is already under way - thousands of police will form three rings of security extending from the Green Line marking the border with the West Bank, through to Israeli city centers, a police statement said. District forces have been ordered to be on the lookout for any Palestinians who have infiltrated from the West Bank, as part of the police's security preparation. "There are no concrete terrorist threats, but there are general alerts," Jerusalem Police spokesman Shmuel Ben-Ruby said. "Preparations this year are larger in scope than previous years, because of the ongoing security incidents around us." Thousands of police, Border Police and volunteers will help secure the capital, including increased patrols at hotels and synagogues. Markets will also be a focal point of police presence, as well as the Old City and roads leading into east Jerusalem. "We will secure worshipers at the Western Wall and pilgrims who arrive at the Temple Mount for Birkat Kohanim [the Priestly Blessing]. There will also be Christian religious marches, and next week a flame will be lit at the Church of the Holy Sepulcher. We will provide security for all of these events," Ben-Ruby said. The Northern Police District will deploy over 1,500 police officers each day to increase security and direct traffic ahead of the holiday, spokesman Moshe Weitzman said. "Today, we have deployed police in shopping centers and other crowded places that attract Pessah shoppers. The presence of officers means there are professional eyes around. We also call on the public to report any suspicious movements, people, or packages," he said. The high alert level will last through to the end of holiday and into the Mimouna - the traditional post-Pessah Sephardic celebration, which will be marked across the country. Weitzman called attention to the increased risk of burglaries during the holiday, as many families leave for vacations and leave apartments and businesses unguarded. "We will deploy officers and undercover agents to prevent break-ins, and we call on the public not to leave valuables lying around their homes. Ask someone you trust to keep on eye on your home," he recommended. While the rest of the country celebrates Pessah around the Seder table, thousands of police will be on the streets and will receive no extra salary bonuses for doing so, Weitzman said. "That's how it is - some police officers will rest, others will work according to shift schedules. We must provide 24-hour protection. We're doing our utmost so that citizens feel safe. I hope the holiday passes peacefully," he said. The Southern Police District, which is the country's largest and contains Sderot and Ashkelon, will also go on a record level of alert over the holiday, the district's Operations Commander Peretz Amar said. "We have a number of front lines with Gaza and Judea and Samaria, and we will be on the lookout for attempted infiltrations into Israel. Every attempt to cross into the country requires us to respond with roadblocks and to work with the IDF," Peretz explained. The Southern District has created three security zones on the southern border, stretching from Eilat to the Rafah border crossing, and has prepared for the eventuality of an attempted terror attack from the Sinai Peninsula, Peretz said. Increased police presence will also be felt at the Dead Sea and in the Ein Gedi region, he added. The South's many natural scenic spots will attract many visitors, requiring increased security, Peretz added. In Tel Aviv, police announced the completion of holiday preparations, which include the placement of roadblocks at the entrance to the city and checks of all incoming vehicles. Police sapper units will also patrol the city's streets, searching for suspicious cars. Also Wednesday, Tel Aviv Police arrested 61 Palestinians who had entered the country illegally and four people suspected of employing them.