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 .
NEW : A Chinese ship picked up a signal on Friday and Saturday , 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 10 military planes , two civil aircraft,13 ships will assist in Sunday 's search .