Schools in North District say they have been overwhelmed by the number of cross-border pupils, despite increasing their capacity to cope with an expected surge.
Their ranks have been boosted by children reaching school age who were born in Hong Kong to mainland parents. And pupils unable to find places in the district are heading for other districts further from their homes in Shenzhen.
Nine of the 28 schools in the district have expanded but principals say it is not enough.
The situation has angered North District residents whose children are also unable to find places in nearby schools and have had to seek places in districts such as Tai Po and Yuen Long.
Chan Siu-hung, headmaster of Wai Chow Public School in Sheung Shui, said there was discontent in the community. Some parents had blamed pupils from across the border for the lack of places.
"They come to beg for our school to take them in, but all the seats are full," he said. "There's nothing I can do."
According to the Education Bureau, nine schools have increased capacity by the equivalent of 11 classes.
But Tai Po District Primary School Heads Association chairman Chu King-yuen said this was not enough.
"The cross-district situation is more and more common because every classroom in North District is full. They trickle down to Tai Po district," he said.
Officials have warned that the demand for primary education places is set to fluctuate when children born to mainland parents reach primary school age and because of a general rebound in pupil numbers.
The bureau said 3,600 children applied for a Primary One school place in North District for this academic year, including 1,400 cross-border pupils.
Liu Chi-leung, headmaster of Fung Kai Kindergarten in Sheung Shui, said that on average, 4.7 pupils sought each place at the school.
"Of course, we understand the parents' rage. Imagine living right next to a school but the child has to attend school in Tai Po," Liu said.
Liu said parents tended to blame cross-border pupils but it was important to remember that many were Hong Kong residents by birth, regardless of whether both parents were residents.
"Discrimination or labelling does not exist in a child's world … parents should not single this group out. They should treat them like everyone else."