It's a sunny Tuesday morning in Tel Aviv and on the corner of Rehov Levinsky and Rehov Yesod Hama'alot, opposite the Central Bus Station, sits a white, fairly unassuming mini-van belonging to the recently inaugurated Immigration Authority's Oz Unit. Three young men - two dressed in the blue, police-like Oz uniforms and one in plain clothes - stand near the van casually stopping passersby who look obviously foreign. "Hello," they call out politely in thick accented Hebrew to the Filipinos, Chinese, Nepalese, South American and African workers who flock by, either enjoying a day off or running errands for their employers. "Please show us your passport." "I've learned to say it in several languages," jokes Hanan Ram, head of this particular Oz unit, which is one of four teams patrolling throughout Israel and whose job it is to seek out the estimated 250,000 foreigners who have either entered the country illegally or violated Israel's strict work visa policy. "We're looking mainly for those whose visas have expired," he explains, adding that most migrants are granted a five-year, three-month stay in Israel before they must return to their country of origin. "We don't deal with the Sudanese or Eritreans," Ram gestures as several obviously African-looking men pass by. "Refugees or asylum seekers are not what we are looking for. We want to find those who have violated their stay here or are here illegally." It's been six months since the Interior Ministry took over the task of cracking down on illegal migrants and set up the Immigration Authority, with its roving Oz Units. According to figures from the Interior Ministry, only 90,000 migrant workers out of some 340,000 foreigners in Israel today have the right to work here legally. Those employed as caregivers, who are mainly from the Philippines or Nepal, can extend their visas for as long as they are needed, but all others - agricultural and construction workers - must leave as soon as their permits end. Seeking out illegal migrants was formally the task of the Israel Police, which came under continual criticism for being too harsh and treating the workers like criminals. The Immigration Authority, however, according to Ram and his two colleagues, Assaf Yamini and Koby Gabriel, has a totally different approach. "There has been lots of fiction written about us," Ram, who until joining the unit last May worked in hi-tech, informs me, between inspecting passports. "But we are just implementing government policy, that's all." He admits that the job is sometimes emotionally disturbing, with people trying all sorts of tricks and scams so that they can stay on in Israel even after their visas have expired. As Ram says this, two young Indian men walk past. One of them hands over a blue Israeli identity card for inspection, and within a few seconds is cleared. The other, however, does not have all the required documentation and, it appears, his visa is no longer valid. "I just arrived from Eilat," he says nervously, flashing an employee card for the Fattal Hotel Group. Ram waves for him to put it away and starts to make several calls back to clerks at the Interior Ministry, in an attempt to verify this man's status, but there is not enough information. The young Indian tells the officers that he is soon to be married to an Israeli woman and that he is just on his way to sort this out. But it is clear that both he and his friend are on edge. Their story has many loopholes. The man with the Israeli ID card refuses to disclose his name to me but says that he got married here less than a month ago and is currently undergoing a process of naturalization. "We are encountering a growing number of fictional marriages," explains Ram, as he orders the man without the required documents to get inside the mini-van, to be transferred for further investigation to the Immigration Authority's head office in Holon. "We see it all the time," he continues. "People get to the end of their visa and then simply pay someone to marry them, in order to obtain permanent residency. Once they have applied for this status or they get pregnant, we can't touch them." "I can't blame them for wanting to stay," says Ram. "Life in their country is so bad, and they know they'll get a better life here. They'll do anything to stay." While Ram and his team claim that, under the auspices of the Interior Ministry, what they are doing here today is totally different from the methods of the Immigration Police, non-profits working the field on behalf of foreign workers, asylum seekers and illegal migrants see the Oz Unit in exactly the same light. "The truth is that we do not see a huge difference between them and the police," comments Shevy Korzen, executive director of the non-profit organization Hotline for Migrant Workers. "They are still going out on the streets and have been told to arrest people whether it makes sense or not." She adds, "They are going after the wrong people. They are harassing migrant workers instead of dealing with the root causes such as the employers and manpower agencies that bring them to work here." According to Korzen, it's government policy that should be tackled and not the growing number of foreigners in Israel searching for a better life. Back on the streets near the bus station, Ram and his crew are still stopping foreign workers. "It's not easy work. We are, after all, dealing with human beings and they are scared, but on the other hand there are rules that need to be followed," says Yamini. "When we had our initial training we were told many things by the police, but when we got out on the streets we realized it was very different to what we'd been told. But we're learning new tricks everyday." Despite the obvious affinity for the rules and the belief in sticking to them at all costs, for the most part the three Oz officers approach the people in a relaxed non-threatening way. Even as they slowly load up their mini-van with foreigners who do not have the required documents, they laugh and joke with those they've detained. As the unit heads back to the office, there is still a lingering fear among foreign workers on the streets here, who have witnessed their work today. "I have nothing to hide," boasts one Nepalese woman, who at the same time refuses to give her name. "I came here legally and am leaving soon because my visa is up. I am just trying to stay away from any police, and I hope that I will be able to renew my visa and come back here," she adds, making the sign of a cross on her chest.