Apple manufacturer Foxconn was today taking extraordinary measures to safeguard its business and workers following a spate of suicides at its sprawling plant in southern China.

Workers have reportedly been told to sign letters promising not to kill themselves and even agree to be institutionalised if they appeared to be in an "abnormal mental or physical state for the protection of myself and others".

Protesters from several workers' rights groups throw paper money in front of paper figures, depicting workers who recently died in apparent suicides, during a traditional Chinese mourning ceremony outside a Foxconn office in Hong Kong.

Nets were also reportedly being hung around buildings to deter suicidal employees.

The moves came after a 19-year-old employee fell to his death at the Shenzhen factory on Tuesday -- the ninth apparent suicide at the enormous site this year.