A student protester has been shot in the chest by police in a dramatic escalation in the violent demonstrations that have raged across Hong Kong since June.

The wounded male, a Form Five – or Year 11 – student, was taken to Princess Margaret Hospital after being shot about 4.30pm Hong Kong time during an incident at Tsuen Wan. He was later transferred to Queen Elizabeth hospital in Yau Ma Tei.

The Hong Kong protester was shot in the chest by police at Tsuen Wan.

Officers and first aid staff were seen tending to the teenager on the pavement before he was taken to hospital. Police said the officer shot the protester after he and his unit were attacked by demonstrators.

A security clampdown coinciding with China's National Day and the 70th anniversary of Communist rule failed to thwart the protest movement in the former British colony, with one organiser saying 100,000 people had taken to the streets on Tuesday. Police did not provide an estimate.