Inspector-General of Police Razarudin Husain said five family members of the suspect, aged between 19 and 62, have been arrested to assist in the investigation into the attack, Bernama reported.

Razarudin said they had also detained two students, a 22-year-old man and a 21-year-old woman, who came to the police station at 2.30am just before the attack.

“The duo came to seek advice from the police regarding a sexual assault case that happened two years ago,” he said.

Razarudin said the students were arrested because their actions were suspicious. “The case happened two years ago but they were only trying to seek police advice in the wee hours of the morning.”

Jemaah Islamiyah was behind the 2002 bomb attacks in Bali that killed over 200 people. More bombings targeted the Marriott and Ritz-Carlton hotels in Jakarta in 2009.

Its members reportedly received military training in Afghanistan during the 1990s, and the group is alleged to have ties with Al-Qaeda.

Razarudin said police have identified over 20 Jemaah Islamiyah members currently in Johor following today’s attack.

He said the suspect, who was in his 30s, was found to have made preparations prior to attacking the police station, although he had no criminal record.

The masked suspect reportedly attacked the Ulu Tiram police station at about 2.45am, armed with a gun and a parang. He killed two policemen and injured another before being shot dead at the scene.

Police later recovered a Walther P99 pistol and a HK MP5 rifle from him.

The injured policeman is currently in stable condition, according to Razarudin. The top cop added that security would be tightened at all police stations following this incident.