TOKYO -- More than 7,000 of Japan's foreign trainees fled their jobs last year as employers demanded long hours or failed to pay full wages, but a few Vietnamese interns have found a shelter with an expat who tries to get them back on their feet.

The 7,089 runaways represent a 40% increase from 2016, while the total number of foreigners in Japan's technical internship program rose just 20% to over 274,000 at the end of 2017, the Ministry of Justice says. Meanwhile, 4,226 out of 5,966 workplaces surveyed by the labor ministry last year withheld pay or subjected interns to illegal overtime, a 70% figure that highlights serious problems in the program.

Japan faces a chronic shortage of workers due to its shrinking population, prompting the country to bring in more foreigners to help fill its hunger for labor. But the internship program, a pillar of that approach, leaves foreign workers who want to remain in Japan vulnerable when they encounter trouble.

Bungo Okabe, a 36-year-old who was born in Vietnam and came to Japan at age 8, has established a haven for about a dozen ex-trainee compatriots in an aging two-story house in Fukushima Prefecture, north of Tokyo. The workers left their jobs over punishing hours, violence from superiors and co-workers as well as fears of being sent back to their home country.

On a June visit to the house, in a residential area about half an hour's drive from the local train station, some young people sat in a first-floor room with open textbooks, studying topics such as Chinese kanji characters used in written Japanese.

A Vietnamese woman, also 36, who entered the house in early March said she had arrived in Japan in April 2016. She recalled enduring 14- to 15-hour workdays, with just seven days off a year, as an intern at a sewing factory in Yamagata Prefecture, which neighbors Fukushima to the north. She spoke of being called a slow worker and pressured to go back to Vietnam.

The woman had borrowed the equivalent of nearly $9,000 from the bank to cover the cost of going to Japan, and the low wages she would likely earn in Vietnam left little hope of repaying the loan by returning. Deciding she had to stay in Japan -- both for her own sake and that of her two children back home, aged 10 and 8 -- she ran away from her employer's dormitory.

Okabe, whose Vietnamese name is Pham Nhat Vuong, created the shelter and began taking in former trainees in January after closing an eatery he operated. About 1 million yen ($8,989) raised through crowdfunding let him repair a long-empty private home to house the runaways. He pays most of the costs out of pocket, except for some donations, as the ex-trainees have no source of income and would face difficulty paying for food and lodgings.

When Okabe was 5, his family joined the many people fleeing Vietnam in the decades following the war with the U.S. They came to Japan after a stint at a refugee camp in Malaysia.

He said he "couldn't abandon" the runaway trainees, as they were stuck in a foreign country with no place to call home.

The house in the city of Koriyama is full, but Okabe receives 30 to 40 inquiries a month through social media and other channels from trainees who have heard about the facility. The government-led Organization for Technical Intern Training provides temporary lodgings for trainees who are mistreated at their workplaces. But as of July 19, the service had been used just 10 times.

Though Okabe can offer them safety for a time, the root of the problem remains. Many trainees want to continue working in Japan, but the internship program does not let them switch workplaces of their own will. They also cannot work part-time jobs, unlike students from foreign countries.

Okabe notifies the Immigration Bureau about the people he takes in, then negotiates with related Japanese and Vietnamese institutions on transferring them to other workplaces. So far, he has managed to help two people move. At least 10 are still waiting.

Four of the former interns have secured unemployment benefits through negotiations with the Japanese government's employment services center. But most cannot apply for a number of reasons, such as their former workplaces failing to issue necessary documents.

Some trainees end up fleeing their jobs after coming to Japan without a full grasp of the working conditions. Many former interns who disappeared cited dissatisfaction with pay, according to a 2017 survey by the Justice Ministry. More than a few ex-trainees were found to have worked illegally after vanishing from their internship posts.