RISHON LETZION, Israel (AP) _ Yao, a construction worker from China, stood in his underwear between three policemen raiding his apartment after midnight, desperately trying to explain why he didn't have a passport.

``My boss has it,'' Yao, 33, told officers of the immigration police in broken Hebrew, pointing to a calendar advertising a Tel Aviv construction company. ``Please call my boss.''

In the past year, Israel's immigration police have stepped up such raids; the government estimates almost 180,000 of the 260,000 foreign workers are in the country illegally. Though most came here with work permits, many overstayed their visas and others left harsh employers for unauthorized jobs and live in fear of arrest and deportation.

Prime Minister Ariel Sharon told parliament last week that expelling foreign workers will help create jobs _ unemployment is at 11 percent and rising _ and deportations would continue. More than 22,000 workers have been arrested and deported since September 2002, said Commander Orit Friedman of the immigration authority. Some 46,000 foreign workers left on their own.

Critics of government policy say the expulsions will not make a dent in unemployment; Palestinians, not Israelis, once did the menial jobs in construction, agriculture and service industries now filled by foreigners.

Foreigners make up 13 percent of the labor force in Israel; the Bank of Israel says they cost 40 percent less than Israeli workers.

Despite reports of abuse and exploitation, Israel _ where per capita income is about $16,000 a year _ remains an attractive destination for foreign workers because of low wages at home.

Some 120,000 Palestinians once worked in Israel, but have been locked out by travel bans prompted by three years of Israeli-Palestinian fighting.

Israel's dependence on imported menial laborers runs deep. Sharon's farm, run by his sons, reportedly employs foreigners, and the parliament building is being renovated by workers from China, Romania and Africa.

Over the weekend, about 100 workers were caught in police raids, including a sweep Saturday near Tel Aviv's central bus station.

Police set up barriers in the Neve Shaanan neighborhood, checking passports and visas of hundreds of Chinese workers who had assumed the officers would rest on the Jewish Sabbath.

``We don't have a chance to rest, even on the weekends,'' said Collin, a 28-year-old Chinese worker who uses an English name.

Detainees are sent to holding centers, including a converted seven-story hotel near Nazareth that was closed to visitors shortly after the outbreak of fighting in 2000.

The 500 detainees there can keep their cell phones, said Gilada Halman, who manages the detention center for Israel's Prisons Service. Up to six workers share the carpeted rooms _ a balcony overlooking the Galilee hills on one side, a gated, locked door on the other.

Workers are at the hotel for at least 72 hours while officials check their status, Halman said, but some end up staying for months before being deported.

One detainee, Jiang Ruiting, 35, has been in Israel for seven years and in lock-down for 39 days. He said he wants to go home to his wife and 11-year-old son in China, but needs to collect some $20,000 in wages from jobs as a cook, a nursing home staffer and a library worker.

Jiang paid a manpower company to come to Israel _ some $6,000, a fortune in China. Most workers take out loans to pay the high fees.

``I like it here. I made money here,'' said Jiang, who said he made about $800 a month in Israel compared to $150 monthly in China.

The Israeli roundups intensified in 2002, when the government created a 500-member police force to track down foreign workers and gave it a $50 million annual budget.

The force expels about 2,000 workers a month through arrest. About 4,000 more leave on their own and through a voluntary deportation program, Friedman said.

Critics say even the voluntary program is abusive.

``If you threaten on a day-to-day basis, you come arrest them in front of their families, you break doors, put them in jail, take their passports _ they leave because they are afraid,'' said Amiram Gill of a workers' advocacy group.

The weekend raids in Tel Aviv and the suburb of Rishon Letzion were free of violence, though not intimidation. The officers have orders to arrest anyone not carrying a valid visa, even those, like Yao, whose papers are wrongly being held by their employers.

Twelve foreign workers are among the 435 victims killed in Palestinian suicide bombings in the past three years. Dozens more have been wounded.

Some foreigners work at the heart of the conflict. In the Gaza Strip, where many Thai workers tend the fields and greenhouses in Jewish settlements, two Thais were shot and wounded in 2002 by Palestinian gunmen.

Israel started importing foreign workers in large numbers in the 1990s, a time of economic prosperity fueled by immigration from the former Soviet Union and interim peace agreements with the Palestinians.

Gradually, foreign workers started taking the jobs of Palestinians, and the process accelerated after the outbreak of fighting in 2000.

Israel's dependence on imported laborers is not likely to change, said Efraim Zilony of the Histadrut trade union federation.

``The problem will stay the same problem: You haven't enough workers to take care of the old people,'' Zilony said. ``You cannot send me ... a lawyer ... to work in construction.''