Visitors arriving in the United States by both air and sea were fingerprinted and photographed as Homeland Security Department's new biometric surveillance to prevent terrorists from sneaking in was put in place.

Most foreigners arriving in the country will have two fingers scanned by an inkless device and a digital photograph taken by immigration officials under the new security checks.

Only citizens from 27 countries, mostly European, who can enter without visas, are exempted.

The new regulations that came into being on Monday are part of US-VISIT (United States Visitor and Immigrant Status Indicator Technology) -- a new automated entry/exit system.

They allow security officials to check the passengers against terrorist watchlists and a national criminal database. Exit procedures of US-VISIT will be brought in at air and seaports later in 2004.

"The purpose of the new rules is to make sure our borders are open to visitors but closed to terrorists," Homeland Security Secretary Tom Ridge said. "America has been and will always be a welcoming country, but we will also be on guard."

According to a Homeland Security fact sheet, US law requires that an automated entry/exit system be in place at the 50 busiest US land border points by December 31, 2004 and at all ports of entry by December 31, 2005.