PERTH, Australia — A ship searching for the missing Malaysian jet has detected two more underwater signals that may be emanating from the aircraft's black boxes, and the Australian official in charge of the search expressed hope today that the plane's wreckage will soon be found.

Angus Houston, the head of a joint agency coordinating the search for the missing plane in the southern Indian Ocean, said that the Australian navy's Ocean Shield picked up the two signals on Tuesday, and that an analysis of two sounds detected in the same area last week showed they were consistent with a plane's black boxes.

“I'm now optimistic that we will find the aircraft, or what is left of the aircraft, in the not-too-distant future — but we haven't found it yet, because this is a very challenging business,” Houston said at a news conference in Perth, the hub for the search operation.

TOKYO — Toyota Motor is recalling 6.39 million vehicles globally for a variety of problems spanning nearly 30 models in Japan, the U.S., Europe and other places.No injuries or crashes have been reported related to the recalls announced today.But two reports of fires are linked to one of the problems, a defective engine starter that can keep the motor running.Some vehicles were recalled for more than one problem. The recall cases total 6.76 million vehicles for 27 Toyota models, the Pontiac Vibe and the Subaru Trezia, produced from April 2004 through August 2013.The Pontiac Vibe, which is a General Motors model, is also involved because Toyota and GM made cars at the same plant in California and the recalled model is the same as the Toyota Matrix. It was recalled for a problem with a spiral cable attached to an air bag. It is unrelated to a separate GM recall over ignition switches linked to at least 13 deaths.Subaru is partly owned by Toyota, and the model was the same as the Toyota Ractis.

PRETORIA, South Africa — The chief prosecutor in Oscar Pistorius’ murder trial has urged the athlete to “take responsibility” for fatally shooting his girlfriend, pushing him to look at a police photograph of Reeva Steenkamp’s bloodied head that was displayed in court.Prosecutor Gerrie Nel said today that Steenkamp’s head “exploded” when it was struck by one of four bullets that Pistorius fired through a closed toilet door in his home last year.The photograph showed a side view of Steenkamp’s head, with a mass of blood and human tissue on the back and upper parts. Her eyes were closed. Nel said: “It’s time that you look at it.”Pistorius appeared distraught, saying he didn’t have to look because he was at the scene when Steenkamp died.