The little-known Northwestern Polytechnic University now enrolls more international students than almost any other U.S. college.

If you call the main switchboard number of Northwestern Polytechnic University, a little-known college in San Jose that enrolls almost entirely foreign students, you're greeted with an unusual message. “Thank you for calling Northwestern Polytechnic University," it begins. "If you are from the U.S. Department of Homeland Security, please dial 8.” The message is a reminder that some of Northwestern Polytechnic's students have, in recent weeks, had serious problems with U.S. immigration authorities. In late December a succession of Indian students, most of them bound for NPU and Silicon Valley University, another little-known California college, were denied entry to the U.S. by immigration authorities. Rumors swirled of an “immigration blacklist”; the Indian government said it would take up the matter with U.S. officials. The immigration problems pose a serious threat, because with little fanfare and virtually overnight, Nothwestern Polytechnic has become one of the country's largest importers of international students — 95% of whom are Indian. Last year, 9,026 foreign students had active visas to attend NPU, according to federal immigration data — that's more students than the entire undergraduate population of Harvard, and an increase of 350% from two years earlier, when Northwestern had just 1,200. The number is huge even by the standards of the country's biggest and best known universities. NYU, America's largest host of international students, had 13,178 foreign students in the 2014-15 academic year, according to numbers from the Institute of International Education. Northwestern Polytechnic's 9,026 foreign students would make up the ninth-largest body of international students in the country, according to IIE numbers — above Michigan State University and just below UCLA. Yet few Americans have ever heard of it. (NPU was not included in Institute's report because it did not report its international student numbers, an IIE representative said.) Silicon Valley University, an equally obscure school located just a few miles away from Northwestern Polytechnic, increased the number of foreign students it enrolled by 267% in just a year according to the federal data— from 926 students in 2014 to more than 3,400 in 2015. India's foreign minister, Sushma Swaraj, wrote in a tweet to an anxious student that that Northwestern Polytechnic and SVU were "not blacklisted." "But they are not reputed either," she added. Though they have little academic reputation, both schools benefit from the enduring international appeal of an American education, and from the U.S. immigration system, which takes a liberal approach to dispensing visas to students enrolled in accredited U.S. colleges. They have also benefited from light-touch oversight by the accreditor that has given both the tick of approval they need to bring in so many students. The accreditor, which also oversaw the disgraced Everest College chain that collapsed last year, told BuzzFeed News it now plans to take a closer look at both Northwestern Polytechnic and SVU, in light of "recent focus" on the schools.

At the margins of higher education, schools composed almost entirely of foreign students have long raised suspicions among education and immigration officials. Until recently, the most troubling of these were unaccredited, fly-by-night for-profits, enrolling only 1,000 or so students apiece. Investigations revealed their tiny campuses were virtually empty, with most of their students using their time in the U.S. to work and earn money, then taking classes online or on weekends. In 2010 and 2011, several colleges were shut down by U.S. officials who called them “sham schools,” and their operators — like the president of Tri-Valley University — sentenced for visa fraud.

Now, a new class of colleges are rising in prominence, also catering almost exclusively to foreign students and growing enrollments by triple-digit percentages each year. The schools have real campuses, and require students to attend classes. Most importantly, they are officially accredited. Both Northwestern Polytechnic and Silicon Valley University are accredited, a distinction that allows colleges with many foreign students to avoid the most stringent oversight. Immigration and Customs Enforcement's student visa program depends on the accreditation system: it requires less documentation from accredited schools that want authorization to admit foreign students than it asks of unaccredited schools. And accreditation will soon allow the schools' foreign graduates to stay in the U.S. for longer periods of time — up to three years after graduation, an option that wouldn't be available to students at unaccredited schools. “In some ways, it’s Tri-Valley 2.0,” said Neil Ruiz, a researcher at George Washington University, referring to the notorious college whose founder was jailed for running an immigration scam. This time around, he said, "They're getting more legitimate and sophisticated.”

Northwestern Polytechnic has avoided many of the red flags of Tri-Valley. The school, according to university officials, has strict rules that enable only a few hundred students to get credit for working off-campus, and none of its classes are online. Its president, Peter Hsieh, said it rejects a significant portion of its applicants — some 50% last admissions cycle. The NPU campus is a loose collection of seven low office buildings that are strung out over a half-mile area in the San Jose suburbs. On the second day of the semester, the campus administrative building had the layout and feel of a DMV, with a long, snaking line leading to an information desk that pointed students in the direction of advisers and administrators. The bare-bones classrooms were often crowded with forty or more students. "We're not a diploma mill in any sense," said Hsieh, a lawyer who took over the school from his father. "We could easily profit from accepting everyone regardless of academic performance, but we only accept first-class students." The flood of Indian students in the past three years, which allowed NPU to grow its total enrollment 785%, from just 700 students in 2012, had been a "complete shock to us. We don't know why it's happening." Hsieh theorized that it had to do with the school's location, near the heavily Indian city of Fremont, and its proximity to Silicon Valley. The school doesn't market itself at all, Hsieh said. Thanks to its huge surge in enrollment, NPU took in $40 million in 2014, and spent $12 million — leaving it with a $28 million surplus, according to tax filings. Shubha Dhaeia, a student at NPU, chose the school over a more typical college experience at Santa Clara University. "Santa Clara was huge," she said. "It would have been difficult to come and adapt.” She opted for NPU, she said, because it offered familiarity in a new country, and because her sister lives nearby in Fremont. But many students said they were at NPU for one overarching reason: they hoped it would eventually allow them to work in the United States. Immigration law allows students who have graduated to continue working in the U.S. for long stretches of time after graduation, called Optional Practical Training — a period that will soon stretch up to 36 months for students in many technical fields. And a master's degree from a U.S. university increases the likelihood of getting an H1-B “skilled worker” visa — a separate cap on visas exists for those with advanced degrees, allowing them to bypass the much larger pool of regular applicants.

View this post on Facebook facebook.com In late December, rumors swirled in the Indian media that Northwestern Polytechnic had been put on a U.S. immigration blacklist. To ease fears, the school posted a number of redacted images showing the stamped passports of students who had successfully entered the country in recent days.