Keningau District Police Chief DSP Robert Salisip David said the five foreigners, comprising four Indonesians and a Filipino, were arrested under the Immigration Act for not having any valid identification document.
He said the operation focused on "kereta sapu" (pirated taxi) operators in the district.
"Under Section 33 of the Commercial Vehicle Licensing Board Act 1987, no person shall use any motor vehicle as a public service vehicle unless he or she has a license granted under the Act authorising such use of carrying passengers.
"If found guilty, the offender shall be fined not less than RM1,000 and not more than RM10,000 or imprisonment for a term not exceeding one year, or both," he said.
The operation, which involved three officers, 10 personnel from the Keningau traffic police headquarters and another officer and three other traffic enforcement personnel from the Sabah Police Headquarters in Kota Kinabalu, was headed by ASP Parum ak Niot.
Also present during the operation were Keningau Chief Traffic Inspector Ronaidi Jaffar and Traffic Investigating Officer Inspector James Ding.