Chinese tech stocks plunged on Friday amid rising jitters about IT security.

The cause wasn't immediately clear, but follows a report from Bloomberg that US tech firms and agencies have had data stolen by Chinese spies.

The data had been siphoned off via tiny chips inserted on server circuit boards, the report said.

In morning Hong Kong trading, computer maker Lenovo tumbled more than 20%, while the Hong Kong listed-shares of equipment maker ZTE dropped more than 14%.