I strongly doubt that this is an official military act of the Chinese government. It will most likely turn out that this is not an official military act of any government as the intent was to do this in secret.
Just because the intent was to be secret does not negate an official act of any country. To assume that any military does nothing in secret is naivety at its finest.
Just because the intent was to be secret does not negate an official act of any country. To assume that any military does nothing in secret is naivety at its finest.