Warning comes after alleged ISIL bomber was arrested and brazen attack in neighbouring Indonesia.
Malaysian police have arrested nine suspected members of the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) during a two-week sweep, as part of a crackdown on suspected extremists, a senior official said.
Among those arrested were two suspects in the grenade attack on a bar in the outskirts of Kuala Lumpur in June, which injured eight people, Inspector General Khalid Abu Bakar said on Saturday.
Khalid said the two bar attack suspects had conspired with two others who had already been charged in court in connection with the attack in Petaling Jaya on June 28.
A known Malaysian ISIL fighter in Syria, Muhammad Wanndy Muhammad Jedi, had said in a posting on his Facebook page that the group had carried out the attack.
If the claim was genuine it would have been the first attack by ISIL on Malaysian soil.
Khalid said the two men who carried out the June 28 attack had been caught in the northeastern state of Kelantan, where they had been awaiting instructions from Wanndy to carry out further attacks.
“Following their arrest, police managed to seize a grenade, and it was suspected it would have been used in a planned attack,” Khalid said.
He said two other people had been arrested for helping to hide the suspects.
Police had also tracked down a suspected ISIL member whose cell had received orders from Wanndy, and had threatened attacks on the police headquarters in Kuala Lumpur and on government buildings in the country’s administrative capital of Putrajaya, Khalid said.
According to Channel News Asia, Wanndy, 27, is believed to be operating from al-Raqqah in Syriah and is now number one on Malaysia’s most wanted terrorist list. He reportedly left for Syria in 2014.
Others arrested included a 17-year-old in the eastern state of Sabah, on the island of Borneo, who was believed to have been planning a “lone wolf” attack on non-Muslims after communicating with another Malaysian ISIL member in Syria.
Three foreigners, who were ex-military, were also arrested in Kuala Lumpur for allegedly using the country as a transit point to secure fake travel documents and plan an attack on a Middle East nation, Khalid said.
Khalid said the arrests were made from July 20 to August 9 in Kuala Lumpur, Johor Sabah and Kelantan.
Two weeks ago, Malaysian authorities had cancelled the passports of 68 of its citizens who were suspected of having gone to Syria and Iraq to support ISIL.
More than 200 Malaysians have been arrested by anti-terrorist police on suspicion of ISIL-related activities since early 2013, police records show.