Will people over 70 be detained?

There is no age limit for criminal cases.

Article 21 of the Law on Public Security Administration Punishment: If the violator of public security administration is under any of the following circumstances and should be given administrative detention punishment according to this Law, the administrative detention punishment shall not be executed:

(a) has reached the age of fourteen but under the age of sixteen;

(2) Having reached the age of 16 but under the age of 18, violating the administration of public security for the first time;

(three) more than seventy years of age;

(four) pregnant or nursing a baby under one year old.