PORT DICKSON, Malaysia >> Malaysian authorities have raided a construction site and detained 77 foreigners as part of a fresh crackdown on illegal immigration.

Immigration officials said more than 3,100 foreigners and 63 employers who allegedly hired workers illegally have been detained since a sweep began July 1. The crackdown is targeting migrants who come to Malaysia illegally to work mostly low-wage jobs in the construction, plantation and manufacturing industries.

As one of Southeast Asia’s richest countries, Malaysia has long attracted workers from nearby nations such as Indonesia, the Philippines, Bangladesh and India.

Immigration officials who conducted the midnight raid today and early Wednesday at the construction site in northern Negeri Sembilan state found 77 of the 85 workers had no valid documents. Most of them are Indonesians, living in wooden make-shift dormitories at the site. Reporters were notified of the raid and invited to go along.

The 77 workers were handcuffed and sent to the immigration depot, where they are expected to be deported, officials said.

The new sweep followed the expiry of a deadline to register foreign workers from 15 countries. Officials have said only 161,000 of 600,000 illegal migrants who are eligible to apply for work permits had done so by June 30.

Malaysia, which has a population of 31 million, relies heavily on foreign labor to fill menial jobs shunned by locals. There are some 2 million registered foreign workers in Malaysia and another million believed to be working illegally. The government regularly seeks to flush out the illegal workforce, but this had previously caused labor shortages in certain sectors.

Immigration chief Mustafar Ali has said that some 30,000 illegal migrants were deported this year. He warned that employers who hire illegal migrants could be caned, in addition to facing prison time and fines.