A 2.8-magnitude earthquake with its epicentre in Deep Bay rattled Shenzhen and Hong Kong at 2.42pm yesterday.
The Hong Kong Observatory received more than 100 reports from members of the public, jamming its hotline briefly.
Most of the calls were from people living or working in Tuen Mun, Tai Po and Sheung Shui in the New Territories, near Shenzhen.
Observatory scientific officer Woo Wang-chun said the tremor was a minor one that lasted a few seconds with at least one aftershock.
The epicentre was about 30 kilometres northwest of the Tsim Sha Tsui-based Observatory.
One woman working in a Kwai Chung office when the quake hit, said: 'My colleagues and I were petrified for a brief moment before we recovered our composure and realised it was an earthquake.'