Police have blamed several recent high profile robberies and murders on Indonesian fly-by-night gangs, who arrive in boats across the Strait of Malacca, commit robberies and flee back with their loot.
The gangs favour the Lunar New Year balik kampung or 'return home exodus' when close to a million people head out of the capital for holidays, leaving their homes unattended.
Interpol is routinely informed but experts said it is nearly impossible to track or apprehend the culprits once they re-enter Indonesia and melt into the population.
Two high-profile robberies, last week and on Tuesday, by suspected Indonesian gangs forced the police to set up a special taskforce to combat the menace.
Albert Mah, 82, a highly decorated former senior police officer was beaten to death while trying to defend his family against a gang who broke into his house in Kuala Lumpur last week. The gang then tied up the family and escaped with cash and jewellery.
On Tuesday, another senior retired police officer lost cash and jewellery to another gang that ransacked his house while the family was out for dinner.
Besides Indonesians, a Thai gang also crossed overland last month and robbed a goldsmith, killing a guard. But police got a lucky break and arrested five Thais and recovered M$1.6 million (HK$3.57 million) in cash and gold bars just before they crossed back into Thailand.