KUALA LUMPUR - According to police sources, the five included a man who was slightly injured in the blast.
"We do not believe them to be the bombers but we need them to help us in the investigation," said a source.
City police chief Senior Deputy Comm Datuk Tajudin Md Isa said the five men, aged between 25 and 46, were nabbed at about 6pm on Wednesday.
The blast at 4.25am on Oct 9, which had been linked to a turf war between rival gangs, ripped through the front of the nightclub along Jalan Bukit Bintang, killing 36-year-old car jockey Tiong Kwang Yie and injuring 12 others.
Four vehicles were damaged in the blast.
The injured, aged between 31 and 56, included a Thai man, a Singaporean male, and four women from China.
All 12 have been discharged from the Kuala Lumpur Hospital, according to a spokesman.
It is learnt that triad kingpin Ah Hai was at the scene at the time of the incident, but escaped unhurt when a second hand grenade that was thrown from the second floor of a building failed to explode.
The 53-year-old was reported to have led an underworld gang for more than two decades.
He is believed to be from Gang 21, which has been running illegal businesses here including gambling.
Ah Hai later turned himself in to have his statement recorded on Monday.