Police denied the bomb explosion incident in Bukit Bintang early today was related to the Islamic State (IS) militant activities.

Instead, Kuala Lumpur police chief Datuk Tajuddin Md Isa said the explosion was believed to be caused by a fight over a business territory between gangster groups.

"It is still early to say...but we believe that it was related to a fight over a business territory between gangster groups.

"However, we can assure that whole area is now safe," he told reporters after visiting the scene here today.

A 36-year-old car jockey, Tiong Kwong Yie, was killed, while 12 other people, including foreign tourists, were injured in the 4.20 am explosion of a handmade grenade in front of a nightclub at the Sun Complex in Bukit Bintang here.

The incident is believed to be the first to have occurred at an entertainment outlet in the country.

Tajuddin said the public need not worry about the safety level in the area and could continue going about their daily activities.

"Police will also increase patrol in the area in a bid to further improve the safety level," he said.

At the same time, he also called on the public not to fall easily for the rumours that there were eights bombs planted in the area.

"As of now, there were only two bombs, not eight as circulated in the social media, don't believe that," he said.

For further information, he said they could always contact the Dang Wangi police headquarters directly.

Meanwhile, Kuala Lumpur Hospital spokesperson said three out of 12 injured victims taken to the hospital were transferred to the Ampang Hospital, while two others were receiving treatment at the Gleneagles Hospital.

The 12 injured victims comprised six local residents, one man from Thailand, one man from Singapore and four women from China.