City deputy CID chief Asst Comm Khairi Ahrasa said gangsters could have been behind the explosion, believed to be from grenades, but police are investigating the case from all angles.
A car jockey was seriously injured in the blast and is under intensive care at Hospital Kuala Lumpur. At least 13 others, were injured in the blast and have been warded at Hospital Kuala Lumpur and the nearby Tung Shin Hospital.
ACP Khairi said police received a call from a member of the public at about 4.25am.
"Some of the victims were about to board a Toyota Vellfire when an explosive device fell onto them from the second floor of a building.
"The victims were patrons of a pub and residents of nearby hotels.
"A Toyota Camry, Mazda and BMW were also damaged in the explosion," he added.
The case has been classified as attempted murder under the Firearms Act.
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