Muslim-majority Malaysia has been on the watch for IS-linked militants since an attack last year by the group in Jakarta, the capital of neighboring Indonesia.
Inspector-General of Police Khalid Abu Bakar said in a statement that the six suspects were detained from separate raids in four states from May 23-26.
The first arrest was of Muhammad Muzafa Arieff Junaidi who surrendered after police issued a media statement requesting the public to come forward with information about him. The 27-year-old cow farmer was wanted by police for smuggling arms for Malaysia-based IS militants.
Khalid said Muzafa was instructed to sneak into Southern Thailand with two firearms.
Another arrest involved two brothers – a religious school teacher and online businessman – under suspicion of helping the militant movement in Syria. The brothers are relatives of Muhammad Fudhail Omar, who had instructed a “lone wolf” attack in Sabah last August.
Fudhail is expected to take over the role of the former top IS operative Muhammad Wanndy Mohamed Jedi who was on a US list of global militants until his death, Khalid said.
Wanndy was the alleged mastermind behind a grenade attack on a Kuala Lumpur bar last June which injured eight people. It was the first and so far only IS attack that caused casualties in Malaysia.
Also arrested, a 54-year-old retired military personnel for channeling around RM20,000 to Syrian militants through several transactions. One of his sons has joined the militants in Syria. Another two unnamed suspects were detained for supporting and helping the IS movement in Syria.
All six suspects will be held for further investigation, Khalid said.
Malaysia has arrested more than 250 people between 2013 and 2016 for suspected militant activity linked to IS.