Three Thai nationals, including a woman, and a Malaysian were detained by the authorities and risk facing the death sentence for illegal possession of firearms, news reports said today.

The four were arrested under the harsh Internal Security Act (ISA) and were charged at the Petaling Jaya magistrate court for having five pistols, an AR-15 rifle and 336 bullets, the Star newspaper reported.

Both charges carry the mandatory death sentence upon conviction.

Those arrested were identified as Songsil Udtoom, 37, his brother Jukkis Udtoom, 40, Malaysian Loo Yeong Guang, 30, and his Thai girlfriend Phailin Noochangphueak, 26, the newspaper said.

Nine robberies

They are among seven suspected armed robbers arrested for their involvement in a robbery of a jewellery outlet in Subang Jaya on Feb 3.

Two security guards and a robber were killed in the incident, while the robbers fled with jewellery worth RM890,000, The News Straits Times reported.

The other three gang members, all Thai nationals, were detained in northeastern Kelantan state while on their way to neighbouring Thailand on a bus, the Star said.

Inspector General of Police Musa Hassan said in a statement that the seven of them were part of a 14-member organised gang of armed robbers.

Musa said they were believed to have been involved in at least nine robberies of jewellery outlets and car-jackings in Kuala Lumpur, Selangor, Pahang and Negeri Sembilan states.

"They are also believed to have been responsible for the murder of seven people including six security guards and a member of the public," he said.

The ISA legislation allows for two-year detention periods that can be renewed indefinitely. There are over 100 people under the ISA, more than 80 of whom are alleged Islamic militants.