KUALA LUMPUR (THE STAR/ASIA NEWS NETWORK) - Police will take swift action against those involved in the bomb blast at Sun Complex in Bukit Bintang on Thursday morning, said Deputy Home Minister Datuk Dr Wan Junaidi Tuanku Jaafar.

He also expressed his sympathy to those injured in the incident at 4.30am outside Cherry Blossom club. One Malaysian car jockey died of his injuries, while 12 others were injured.

He said he has yet to receive information on the motive behind the explosion and those who were behind the crime.

"Have faith that the police will take action.

"We have yet to have information on the motive behind the explosion or who was behind it,'' he told the Dewan Rakyat, or House of Representatives, during question time on Thursday.

He said the blast could have been carried out "by locals or immigrants".

"It could also have been due to business rivalry between the clubs in the area... The possibilities are numerous," he added.

Wan Junaidi was answering a supplementary question by Datuk Shamsul Anuar Nasarah (BN - Lenggong) who brought up the incident.

"This is a worrying incident.

"As part of the House, we should express our regret and sympathy to those who were hurt in the blast," said Shamsul Anuar.

Home Minister Datuk Seri Zahid Hamidi also called on the public to remain calm, The Star reported.

Military grade hand grenades were used in the blast but there is no link to terrorism so far, say authorities.

Deputy Kuala Lumpur CID chief Khairi Ahrasa said the hand grenades were likely to have been sourced overseas for the attack outside Cherry Blossom club.

Kuala Lumpur CID Chief Gan Kong Meng said the blast, which killed Malaysian car jockey Tiong Kwang Yie, 36, and injured 12 others, was the work of more than one person and may have involved a business feud. He said police have identified the suspects.

Among those injured were a Singaporean named Wong Kim Teng, two from China and one from Thailand.

The victims were injured by the shrapnels from the grenades. An eyewitness told reporters that the grenade blast left people lying wounded and bloody on the streets.