A thorough investigation into Sunday's fatal bomb blast in Penang is necessary to quell public suspicion and anxiety, said an opposition leader.

The bomb blast in Penang's Pranglin Mall, which killed one man and seriously wounded another, has unnerved residents in the island state.

The homemade pipebomb - filled with bullet castings and nails - exploded at the popular mall's walkway, killing swimming instructor Yeoh Kok Siew, 47, while Wong Boon Tat, 66, who was injured in the incident, has since been warded in Penang Hospital.

PKR vice-president R Sivarasa lamented that Penang Chief Minister Dr Koh Tsu Koon was too hasty to insist that the blast had no connection with terrorist attack, even before police's inquiry was completed.

Koh had initially said that the explosion was caused by a malfunctioning switch-box.

Act of terror

"The blast in Penang was undoubtedly an act of terror, regardless who are the perpetrators," said Sivarasa.

He urged Deputy Prime Minister Najib Abdul Razak, who is also defence minister, to order an investigation into the incident and make its findings public.

"The government should not use the excuse of fearing that foreign investors or tourists might be turned away to conceal the truth. If this case is not handled transparently, the public would perpetually besieged by rumour and anxiety," added Sivarasa.

He said that terror attacks might not be necessarily coming from external or local religious extremists. "Terrorism could crop up in any form or in any place."

According to the opposition leader, in addition to improving the nation's defence apparatus, the government should also be concerned with the discipline of our military and police forces.

"Recently repeated occurrence of arm heists, solders' rampage shooting of innocent civilians , and blatant police abuses of power reflect the serious disciplinary problems within our security forces."

The News Straits Times today speculated that the bomb was planted after an unsuccessful attempt at extortion traders by gangsters.