Malaysian police said nine people were detained on Monday on suspicion of involvement in terrorist acts or forming links with terrorists inside the country and abroad.
National police chief Khalid Abu Bakar said the suspects, aged from 25 to 55, were arrested in several locations in Selangor state, near Kuala Lumpur, and in northern Kedah state bordering Thailand.
"Some of the individuals arrested have taken part in clandestine meetings to strengthen militant ideology, for fundraising and military-style training in preparation for violence," he said in a statement.
No other details were made available.
The Southeast Asia nation has not been the target of major terror attacks, but has been the home of people believed to be linked with militant groups, such as al-Qaida.