I think what you are referring to is what Montag hears in the radio as he is running away. He is running away after he killed Beatty. He knows that the police are after him. As he comes to the ten lane road, he hears one announcement. It is to look out for him. The radio is anouncing that he is a fugitive and people should try to spot him.
A little later, the radio also announces that war has been declared and that the country is now involved in the war that will destroy the city a little later in the book.