Colombia says it has broken up a ring that provided false passports to members of al-Qaeda and Hamas.
Suspects were trailed after Iraqis were found in Bogota
Nineteen suspects were detained during raids in five different cities, said the attorney general's office.
They are accused of forging passports for Pakistani, Jordanian, Iraqi and Egyptian citizens, who could then travel to the US and Europe.
The US co-operated in the police operation and will seek the extradition of some of the suspects, it said.
However, US officials said they were surprised by the alleged links to Islamist groups, as they were only aware of a connection with Colombia's rebel army, the Farc.
"False documents were handed over to persons of Arab origin, who transited Europe with Colombian nationality," said Colombia's Acting Attorney General Jorge Armando Otalora.
"The foreigners were turned into Colombian citizens without ever coming to Colombia," Mr Otalora's office said.
Two of those arrested were said to be immigration officers, and another worked for the government agency that issues identity cards.
The government said it launched its investigation in August 2002, after finding three Iraqis with false passports in Bogota.