A surprise security check in Hong Kong International Airport's restricted area today found 50 people, but no forged documents.

Immigration officers and representatives from the Police, Customs & Excise Department, Airport Authority and security staff participated in the 1am to 4am operation. They were looking for forged passports and other criminal activity.

It was the ninth joint operation since the airport opened.

Immigration officers inspected travel documents to check for forgeries, Customs officers looked for restricted items, and Police dealt with other crime-related matters.

The inspections deter the exchange of forged travel documents in the airport and prevent illegal immigrants from using Hong Kong as a transit point.