Flight MH370 was bound for Beijing with 239 people on board, 154 of them from China. It’s now been over 30 hours since it last made contact with air traffic control. Malaysia’s Department of Civil Aviation said at a news conference that contrary to previous reports, only two passengers had boarded the flight using stolen passports. They are examining CCTV footage from the check-in point to departure.

The Malaysian Airlines CEO dismissed the possibility of a technical problem. He said the aircraft had been repaired by Boeing and was certified safe to fly. A military official said radar indicated that missing flight turned back before disappearing.

In an earlier report, Malaysian authorities had said they were investigating the identities of at least four passengers suspected of using stolen passports. They now say there were only two. Those passports had been stolen in Thailand, one lastAugust, the other two years ago.