IT WAS a Thursday, 11pm, and the parties were getting started at the nightspots popular with expatriates on Yongfu Road, in Shanghai's trendy former French Concession. Then, at upmarket bar The Apartment, the police arrived, about 50 of them. The party stalled. They blocked the exits to the four-storey colonial era building, cut the music and ordered the lights be switched on.

The raid was part of a 100-day crackdown, purportedly on foreigner visa violations, launched weeks earlier in Beijing that has left a bitter taste among many young foreigners here, and raised questions about possible political motives behind it.

M1NT nighclub in Shanghai: one of the city's most exclusive nightclubs.

A Dutch resident who witnessed the raid on The Apartment said police demanded passports from all patrons and recorded passport and visa numbers.

Those without passports or copies of identity documents or who had invalid visas were detained.