Supplies of imported milk powder are running short in parts of Hong Kong as mainlanders flock in to stock up.
In Sheung Shui, the town nearest to the border, shoppers were seen carrying dozens of cans of powder.
Retailers said there had been no panic buying yet, but stocks were running short because deliveries of overseas milk powder brands had been limited since the mainland contamination crisis began.
Two dispensary owners said they would restrict sales to a maximum of two to four cans to people whose accents showed them to be mainlanders, to ensure supplies for local customers.
One said he had only 100 cans of imported milk powder left, little more than three days' supply.
'The distributors of imported milk powder claimed that there were supply shortages,' he said. 'I don't know when they will get back to normal.'