NEW : A Australian ship picked up a signal on Saturday and Friday , authorities say . `` I 'd like to see some additional assets on site quickly -- maybe some sonobuoys , '' he said , referring to 5-inch-long sonar systems that are dropped from aircraft or ships . NEW : An Australian naval vessel is pursuing a more recent detection in a separate location . NEW : An official calls the sounds `` an important and encouraging lead '' but urges caution . Up to two military planes , two civil aircraft,13 ships will assist in Friday 's search .
NEW : A Australian ship picked up a signal on Saturday and Friday , authorities say . NEW : An Australian naval vessel is pursuing a more recent detection in a separate location . NEW : An official calls the sounds `` an important and encouraging lead '' but urges caution . Up to two military planes , two civil aircraft,13 ships will assist in Friday 's search .