Tamils are expats from Tamil Nadu and Sinhalese are expats from Orissa. Basically they have all the Indian connections and forefathers. There is no ethnic group called as Srilankan citizens.
Why are you talking about political situations in places which you're not aware of?
Every Tamilian condemn the terrorist operations of LTTE. But unfortunately this cannot hide the Human Right violations on innocent civilians of the Sri Lankan force and the former(IPLF) in Srilanka.
No terrorist outfit (except cross border terrorism sponsored by Pakisanis), be it AlQueda, or LTTE or PLO aint created without oppression on their own civilans.