Indonesian counterterrorism police have thwarted a jihadist missile attack early Friday, arresting six terror suspects who reportedly planned to fire a rocket from the nearby Indonesian island of Batam into downtown Singapore.

The target of the missile attack was Singapore’s Marina Bay, a busy tourist district and home to one of Asia’s biggest casinos, according to National Police spokesman Maj. Gen. Boy Rafli Amar.

“Yes, there were indeed plans for the attack. But the plans did not materialize,” Amar said.

The six men, between the ages of 19 and 46, allegedly belong to the ISIS-affiliated Islamic terrorist group Katibah Gigih Rahmat (KGR), which helps Indonesian militants travel to Syria. Among the six was 31-year-old KGR ringleader Gigih Rahmat Dewa.

In their plan to fire the rocket missile from Batam, the terrorists allegedly received financial assistance from Bahrun Naim, an Indonesian fighting for the Islamic State in Syria. Naim is thought to be the chief architect of last January’s attack in central Jakarta, which killed eight people.

The arrests took place at various locations across Batam, one of which held a weapons stash.

Singaporean media have questioned the ability of a home-made rocket to travel the 15 miles separating the Island of Batam from Singapore, noting that the rocket would have to be more advanced than the homemade Qassam rockets that Palestinian militants have fired into Israel from inside the Gaza Strip.

Short-range rockets capable of reaching Singapore from Indonesia would include the Grad (range 20km) and WS-1E (range 45km), reports said, adding that these missiles are not home-made but are manufactured in Iran and China respectively.

Following the foiled attack, Singaporean authorities have stepped up national security measures, according to a statement from the Ministry of Home Affairs (MHA).

“In response to this threat and the prevailing security situation Police and other agencies have been stepping up inland and border security measures,” a ministry spokesperson said.

“Our security agencies have been coordinating closely with the Indonesian authorities since the discovery of this attack plot, to monitor the activities of the group and to apprehend those involved,” the ministry added.

“We are grateful for the good co-operation by the Indonesian authorities and their actions to apprehend the group.”

Follow Thomas D. Williams on Twitter Follow @tdwilliamsrome