The biggest problem for border police today is probably boredom, but the boundary has not always been so peaceful.
On July 8, 1967, five men were killed and 11 wounded when officers came under machine-gun fire after a mob attacked the police post.
No Chinese soldiers were involved and evidence suggests it was local militants. But the border remained unsettled with skirmishes at Lowu, Sha Tau Kok and Man Kam To where two off-duty policemen were detained after crossing the border.
Senior police inspector Frank Knight, trying to calm frayed tempers, was seized and taken across the boundary where he was held for 36 days before escaping.
The two officers were returned in November 1967 after talks with Chinese border officials.
Today the mess hall of the border police headquarters boasts a jade sculpture - a gift from the Chinese force across the fence.
