Prime Minister Najib Razak’s statement confirmed days of mounting speculation that the disappearance of the Malaysia Airlines Boeing 777 was not accidental, refocusing the investigation into the flight’s crew and passengers and underlining the massive task for searchers who already have been scouring vast areas of ocean.

Police on Saturday told CBS News that the homes of all of the jetliner’s flight crew were searched after being under surveillance for the last few days. Authorities have said they will be investigating the pilots as part of their probe, but have released no information about how they are progressing.

“Clearly the search for (Flight) MH370 has entered a new phase,” Najib said at a televised news conference. …

“In view of this latest development, the Malaysian authorities have refocused their investigation into the crew and passengers on board,” Najib told reporters, reading from a written statement but not taking any questions.