Malaysian authorities have arrested three people including a Syrian and an Indonesian national on suspicion of planning terror attacks against domestic and foreign targets.
The announcement came a day after the US and Australian embassies had warned their citizens to avoid a popular Kuala Lumpur tourist area on Thursday (local time) due to an unspecified security threat.
The detainees were planning to "attack important national assets, Western assets, and public spots," a statement by Deputy Inspector-General of Police Noor Rashid Ibrahim said.
The statement did not specify their nationalities, but Malaysian news outlets quoted Noor Rashid later telling reporters they were a Malaysian, a Syrian and an Indonesian.
The police statement said one of the foreigners had travelled frequently to Yemen.
On Thursday, the US and Australian embassies warned citizens to stay away from Jalan Alor, an outdoor dining strip in central Kuala Lumpur that is packed nightly with foreigners and locals.
Malaysian news outlets quoted Noor Rashid saying the arrests were related to the Jalan Alor threat, and that the detainees were taken into custody on Thursday.
"The operation is a result from information obtained from suspects arrested previously," the police statement said.
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 Islamic State in its civil war there, and warn they may seek to return home and import its ideology.
Over the past year, police have arrested numerous suspects whom they say were IS sympathisers plotting attacks.