One hundred mainland mothers are forced to drop off and pick up their children at the border every day following a post-handover security crackdown. The mothers pack narrow Chung Ying Street, Shataukok, with their Hong Kong-born children, who attend Cannan Kindergarten, five minutes away on the SAR side of the border. Teachers then shepherd the children, aged between three and six, to class. Before July 1, mothers could cross the border to take their children to kindergarten. The street arrangement, half in the mainland and half in the SAR, was set up to prevent school runs being infiltrated by illegal immigrants. 'We used to collect our children directly from the kindergarten. But we can't do that now,' one mother said. 'It's inconvenient. The street is so narrow and many of us have to wait here every day.' Another said: 'Some mothers have not even seen what the school is like.' A Security Bureau spokesman said about 800 Hong Kong-born children lived with their mothers in Shenzhen, adding that Chung Ying Street was not a proper immigration control point. Border District Commander Chief Superintendent Tse Chan-fai said school buses might have to travel to Shenzhen via the checkpoint at Shataukok. Shataukok police arrested 15 pregnant illegal immigrants in the first four months of the year, many of whom had walked across Chung Ying Street. The figure for the whole of last year was 45.