The attack on the Movida bar in Puchong, a town on the outskirts the capital, Kuala Lumpur, took place in the early hours of Tuesday morning, when customers were watching live screening of the Euro soccer tournament.
Selangor state deputy police chief Abdul Rahim Jaafar told reporters the suspected motive was either business rivalry, revenge, or a target killing.
"We are still investigating who the suspects are, but the motives could be business rivalry, revenge, or one or more of the victims could have been a target," he said.
In a similar attack in 2014, a man was killed while 12 others were wounded when a bomb exploded outside a pub in Kuala Lumpur.
Related news:
> Blast from "self-made" explosive injures three in Shanghai airport