Officials at a mine in New Zealand where 29 men remained trapped for the second day, say air tests have not yet shown it is safe for rescuer workers to enter.Speaking at a press conference, Regional Police Commander Gary Knowles said tests were being carried out on samples of gas taken from in and around the mine.Mine chiefs say they remain positive that the men would be found alive and rescuers were ready to go in as soon as they were given the all-clear signal. New Zealand's Prime Minister John Key said bringing the men out of the Pike River mine remained the top priority. There has been no contact with the men since they were trapped.