is there a specific process for pakistanis to get an L VISA ?

my husband is Pakistani and we live in Sudan, so we went to the Chinese embassy in Khartoum to apply for an L VISA. they told us that it can be out for me but not for my husband because he is Pakistani, and they said that he needs an invitations letter stamped from the governor of the state to which we are gonna visit in china. the issue is that we don't know any body in china. we are just going for tourism !!