MIAMI -- As many as 100 illegal immigrants awaiting their day in court will be released from jail in Florida if they wear electronic monitoring devices in the biggest such experiment in the country.

The Bureau of Immigration and Customs Enforcement began a six-month test of the ankle bracelet program in South Florida in August for possible nationwide use.

The monitoring devices were assigned to "low-risk, nonviolent alien offenders," said agency spokeswoman Barbara Gonzalez. "We hope to use these devices to release nonviolent aliens into the community while still ensuring the appearance in court as required."

About 60 people were assigned the devices earlier this year in Detroit and Anchorage, Alaska. South Florida is a huge immigration gateway.

Electronic devices have been routinely used around the country for many years for ordinary criminals.

The device looks like a large plastic watch and has a black box that sends a signal to federal officers. Immigrants cannot take the ankle bracelet off, even to sleep or shower.

Yen Chen, 47, a Pakistani immigrant, was detained for about two months in Florida before he was asked if he wanted to participate in the program.

"How could I say no to this offer? ... It's better than being held in custody," Chen said.

He has been under a deportation order since the mid-1980s after immigration authorities discovered he had overstayed his visa.

Chen can leave his home five hours a day with the device but must stay home Saturdays.

Some immigrant advocates have criticized the program.

The use of ankle bracelets for asylum seekers who have committed no crimes and have simply come to the United States in search of protection from human rights abuses is a "misuse of valuable resources and an unnecessary security measure," said Cheryl Little of the Florida Immigrant Advocacy Center.