Jakarta tyre repairmen 'dropping nails'
20 March 2014 Last updated at 10:43 GMT
With more than 70 million motorcycles on Indonesia's roads, mending punctured tyres is big business - especially in the capital, Jakarta.
Police believe some tyre repairmen are paying suspected criminal gangs to throw nails onto the roads in an effort to drum up more business.
Now a community group is trying to make the roads safer by using home-made magnets to clear them of nails and other sharp objects.
Christine Franciska reports.