NILAI (BERNAMA) - Malaysia's Customs department arrested 18 foreigners and seized a massive haul of drugs valued at RM18 million (S$6 million) in a raid on a makeshift store in Kajang, Selangor, last Friday (Jan 26).

The drugs, heroin and ketamine, were found in 37 sacks, with each sack weighing about 25kg, Customs director-general Subromaniam Tholasy said on Monday.

The Narcotics Branch of the Customs headquarters conducted the raid at 11.30pm on Friday following a public tip-off, he said at a press conference.

Datuk Seri Subromaniam said the foreigners arrested were aged between 18 and 50. Ten were Pakistanis, four were from Myanmar and four were Indonesians. Only seven of them had valid travel documents.

They were caught in the act of unloading 1,885 white sacks from two containers to be kept at the store, he said.

The sacks were said to contain salt, and were brought into Malaysia through Port Klang on the west coast of Peninsular Malaysia.

When the sacks were examined, 31 of them were found to contain heroin weighing 766kg, while another six sacks contained ketamine weighing 114kg, he said.

Mr Subromaniam said the sacks had come from Karachi, Pakistan. He did not rule out the possibility that a foreign syndicate was involved.

"However, we are investigating whether Malaysians were also involved," he said.

He did not rule out the possibility that Malaysia was being used as a transit point by drug-trafficking syndicates.

Mr Subromaniam said the suspects were being remanded for seven days from Saturday.

He also said that the case was being investigated under section 39B of the Dangerous Drugs Act 1952, which provides for the mandatory death sentence upon conviction.