The Immigration and Emigration Department took them to the expat detention centre in Hulhumalé on Thursday, the Maldives Independent reported citing the department's media official Hassan Khaleel.
It was a routine operation, Khaleel told the newspaper.
Bangladeshi expatriate workers in Maldives told bdnews24.com that most of them detained migrants were from Bangladesh.
They could not confirm the number of detained Bangladeshis.
According to the Maldives Independent, around 60,000 of the 130,000 migrant workers in the country are undocumented, and most of them are from Bangladesh and India.
They work in the construction and tourism sectors, the newspaper said.