Myanmar governement "lying" over deaths September's demonstrations?

Burma's Junta has acknowledged 10 deaths in the crackdown on demonstrators in September. According to reports from the Human Rights Watch there were 20 documented killings with witness of hundreds more. This brings back a vague memory of the Burmese government's response to the earthquake in December 2004. All the numbers are unfortunate! Why lie about it?

http://www.cnn.com/2007/WORLD/asiapcf/12/07/myanmar.crackdown/index.html