The Tokyo Regional Immigration Bureau booked 1,040 foreigners in the metropolitan area for allegedly violating the immigration control law during an intensive crackdown between May 15 and June 2, the bureau announced Wednesday.

Immigration officers from across the country searched 271 locations in Tokyo and eight neighboring prefectures during the nearly three-week sweep, they said.

The bureau has conducted such campaigns in the Tokyo metropolitan area twice a year since 1997.

This time, 728 people were held for overstaying their visas and 228 for illegal entry, they said, adding that all of them will undergo administrative deportation procedures.

According to the bureau, 968 of the foreigners were working without proper visas, mainly men working as manual laborers. Many of the women apprehended were engaged in "entertainment activities" such as working as hostesses.

Satoshi Murata, a lawyer who works on human rights cases involving people with expired visas, denounced the crackdowns as a crude method of intimidation. He said they are proof that the government has no ability to address problems regarding illegal immigrants at the policymaking level.

He said such intimidatory efforts only lead to an endless game of cat and mouse, and unless the government carries out drastic policy changes, such as granting amnesty to over-stayers who meet certain criteria, their number, currently estimated at 250,000, will not decrease.