I'm getting an error while dropping the materialized view -

drop materialized view viru
*
ERROR at line 1:
ORA-12003: snapshot "INFINITY"."VIRU" does not exist

i've also tried drop snapshot but the same error

and if try to do
DROP TABLE VIRU
*
ERROR at line 1:
ORA-12083: must use DROP MATERIALIZED VIEW to drop "INFINITY"."VIRU"

any one .......