This includes a Singaporean citizen, 59-year-old Rosna Jantan, the mother of the attacker, Berita Harian reported.
The others charged were the assailant’s father, Radin Imran Radin Yassin, 62, and siblings, Radin Romyullah, 34, Farhah Sobrina, 23, and Mariah, 19.
All five were charged separately at the Johor Bahru sessions court today.
Radin Imran was charged with four counts of inciting the commission of terrorist acts, under Section 130G(a) of the Penal Code.
According to the charge sheet, he was accused of spreading the IS’s ideology to his family, including 21-year-old Radin Luqman, who killed two policemen in the Ulu Tiram station attack.
Radin Imran’s eldest son, Radin Romyullah, was charged with two counts of the same charge, while Radin Imran’s wife and two daughters faced one count each.
During proceedings before judge Che Wan Zaidi Che Wan Ibrahim, Radin Imran repeatedly denied the first charge which was read out by an interpreter and expressed dissatisfaction with the details of the charge.
He later said he did not understand the charge, and that he and his family had lived in isolation since 2014.
Che Wan Zaidi then explained to the accused that today’s proceedings were only for the mention of the charges, and that he had not yet been found guilty.
Radin Imran then denied the second charge of supporting acts of terrorism through the storage of four self-made rifles, saying he owned no firearms.
The judge again clarified that he was simply being charged and that he could appoint a lawyer to defend him during the trial. The remainder of the proceedings continued smoothly.
On May 17, Radin Luqman stormed into the police station armed with a gun and parang and killed two constables, Ahmad Azza Fahmi Azhar, 22, and Syafiq Ahmad Said, 24.
Another policeman was injured in the 2.45am incident.
The assailant, who was shot and killed at the scene, was previously suspected by police of being a member of Jemaah Islamiyah (JI). Home minister Saifuddin Nasution Ismail however denied the claim.
JI co-founder Abu Bakar Bashir also denied any links with the attack, which he strongly condemned.
Radin Luqman’s five family members were previously detained under the Security Offences (Special Measures) Act 2012.
Inspector-General of Police Razarudin Husain also previously denied that any of the five were Singaporean.