Malaysian authorities have arrested four suspected militants and confiscated a weapon along with Islamic State group (IS) documents, national police chief Khalid Abu Bakar said Saturday.

Security forces have been on high alert in the predominantly-Muslim country in the wake of deadly coordinated attacks in neighbouring Indonesia earlier this week that were claimed by IS. Seven people, including five assailants, were killed during the incident.

‘Congratulations E8 CK (anti-terror unit) for arresting one male suspect on Friday at a train station.... Weapon and IS documents were confiscated (from the suspect),’ the police chief said on his Twitter account.

The train station is located near the iconic Petronas Towers in the heart of the capital Kuala Lumpur and houses a huge shopping mall frequented by foreigners.

The country's counter-terrorism assistant director Ayob Khan Mydin Pitchay later confirmed to AFP that a knife and IS documents were confiscated at the suspect's house.

In a statement, Khalid said the 28-year old Malaysian admitted that he was planning to be a suicide bomber.

‘The suspect admitted that he had planned a suicide attack in Malaysia and was awaiting instructions from a member of IS in Syria,’ he said.

The police chief added that on January 11, three Malaysian IS suspects were arrested by security forces after being deported from Turkey.

‘They were first detained in Turkey while attempting to sneak into Syria to join IS fighters,’ Khalid said. 

Earlier this week, local media reported that a 16-year-old boy clad in militant attire held a woman at knife-point at a supermarket in northwestern Malaysia.

‘Investigations revealed that he was influenced by the IS movement through social media and wanted to prove that he was capable of such acts by threatening the woman,’ Khalid said.

The teenager was later arrested and is being held in police custody.

Muslim-majority Malaysia practises a moderate brand of Islam and has not seen any notable terror attacks in recent years.

But concern has risen in the multi-faith nation over growing hardline Islamic views and the country's potential as a militant breeding ground.

Authorities say dozens of Malaysians have travelled to Syria to fight for the radical IS group and warn they may seek to return home and import its ideology.

Since 2015, police have arrested numerous suspects whom they say were IS sympathisers plotting attacks.

Opposition lawmakers, however, say the terror arrests have been shrouded in secrecy, making it difficult to gauge the actual threat level.