Malaysian police have arrested another 11 individuals, including seven who were detained with help from the Singapore police, in connection with the brutal murder of a suspected secret society leader at a Johor Baru petrol station on Sunday.
This brings the total number of those detained to 13.
Johor police chief Khalil Kader Mohd said seven people - four men and three women - were picked up in Singapore on Wednesday, while another four men were nabbed during a special operation in Johor yesterday. The suspects are between the ages of 16 and 26.
"We have arrested more suspects who we believe are able to assist us in our investigations," Datuk Khalil told The Straits Times.
In a statement yesterday, he said police are also tracking down several other individuals.
In response to media queries, the Singapore Police Force (SPF) said yesterday that it received a request for assistance from the Royal Malaysian Police (RMP) regarding the murder case.
"The SPF had arrested a total of seven Malaysian suspects, aged between 19 and 23, and they have been handed over" to Malaysian police. SPF added: "It is inappropriate to comment further as investigations by RMP are ongoing."
The Malaysian police's first two arrests - involving a man and a woman - were made on Wednesday, three days after the attack.
The violent killing of the man in public, named as Mr Tan Ah Choy in media reports, has shocked Malaysians, with the authorities not discounting the possibility that it was an assassination.
The victim was stabbed, and then run over twice by a white BMW at the Taman Pelangi Shell station, about 4km from the Causeway.
Home Minister Ahmad Zahid Hamidi told reporters on Tuesday that the victim was the leader of a criminal gang and the attack had allegedly stemmed from a turf dispute between two rival groups.
The Malay Mail Online news site said the 44-year-old was involved in illegal money-lending activities and had a long list of drug-related offences.
Magistrate Noor Aisyah Ahmad yesterday granted a seven-day remand order for the first six suspects - five men in their 20s and a 19-year-old woman - when they were brought to a Malaysian court.
On Sunday evening, the victim had stopped at the petrol station to pump air in his car tyres when he was assaulted by four men who alighted from a white BMW 5-series car. He was dragged to the assailants' car but he fought back.
An 82-second video clip of the incident recorded by a bystander shows that during the scuffle, the victim was stabbed and left lying on the ground. Firecrackers were then thrown from the car towards where the victim lay.
The assailants' car circled the petrol station and ran over the man, before reversing and running over him again.
The car then sped out of the station, stopping briefly for one of the assailants to get in before fleeing.