Meaning of ANNOUNCE in English
BAD : The following day their father suddenly announced them that he was leaving.
GOOD : The following day their father suddenly announced (to them) that he was leaving.
After announce , use to before the listener: 'Shortly after losing the heavyweight title, he announced (to the world's press) that he was retiring from the ring.'
Longman Common Errors English vocabulary. Английский словарь распространенных ошибок Longman. 2012