Inspector-General of Police Khalid Abu Bakar tweeted that the suspects were detained by the Special Branch Counter Terrorism Division personnel yesterday.
The police chief did not give further details about the suspects' nationalities and what exactly they had been plotting.
"As I mentioned before, I will never allow Malaysia to be a transit point or hideout for any terror groups," the police chief said.
The arrests came as there has been a rise in Malaysian citizens joining the dreaded Islamic State outfit in Iraq and Syria.
Rights groups have criticised the move as a revival of a controversial security law that was repealed in 2012 and warned the proposed laws could severely curtail civil liberties.
So far the authorities have detained nearly 100 people believed to be the supporters of IS group.