Police arrested three PSM members including party secretary-general A Sivarajan as well as a Solidariti Anak Muda (Samm) member for holding a candlelight vigil outside the Johor Baru Utara police district headquarters last night.

PSM's E Nalini told Malaysiakini this evening that the four were arrested outside the police headquarters at 7.45pm, just about 15 minutes after police released detained PSM central committee member Khairul Nizam Abdul Ghani.

The other two PSM members were identified as Silvarajah Erusam and Saiful Adli Jamian while the Samm member was Mohd Afiq Ayob.

"They were arrested under Section 9 (5) of the Peaceful Assembly Act for holding a candlelight vigil outside the police headquarters last night in solidarity with Khairul Nizam," Nalini said when contacted.

Malaysiakini understands that about 20 people turned up for the vigil.

Sivarajan was released by police at about 10 pm after two hours in police custody during which it was determined that he was not present at the vigil last night.

"They (the police) checked their videos and determined I wasn't there. But they seized some placards from me which they think were used last night," said Sivarajan said when contacted.

He said the other three will likely be held by overnight by police.

PSM central committee member S Arutchelvan said the detentions were unnecessary.

"It was just a candlelight vigil that people normally attend [...] there was no need to detain them," he told Malaysiakini .