The seven—two Malaysians and five Filipinos—were arrested between March 8 and March 12 in Sabah and Selangor states, Inspector-General of Police Khalid Abu Bakar said in a statement Monday. Two of the suspects, including the immigration officer, are women.

According to Mr. Khalid, the officer, 31 years old, arranged for people without valid travel documents—including Islamic State militants from Indonesia and Malaysia—to enter Sabah before heading to the southern Philippines, site of a long-running insurgency by the Islmamic State-allied Abu Sayyaf group.

Three of the Filipinos hold permanent-resident status in Malaysia. One collected funds for Malaysian Islamic State members Mahmud Ahmad and Mohamad Joraimee Awang Raimee, Mr. Khalid said, while the other two—a female ferry-ticket seller and a laborer—helped smuggle three Indonesian Islamic State militants to the Philippines.

One of the other Filipino suspects has sworn allegiance to Abu Sayyaf senior leader Isnilon Hapilon, Mr. Khalid said, while the last, a car mechanic, was planning to go to Syria to join Islamic State.

The other Malaysian suspect was deported from Turkey, where authorities had arrested him on Jan. 16 for trying to enter Syria to join Islamic State, Mr. Khalid said.

The suspects were unavailable for comment and it is unclear whether they have legal representation. All seven suspects were arrested for offenses related to terrorism under special security laws that allow indefinite detention without trial.